OPINION
¶ 1 In this personal injury action arising out of a one-vehicle rollover accident, plaintiff/appellant Carol Larsen appeals from a judgment entered on a jury verdict in her favor finding damages in the total amount of $6,050,000, but determining that defendants/appellees (collectively referred to as “Nissan”) were only eight percent at fault. The primary issues on appeal are whether this court correctly interpreted A.R.S. § 12-2506 in Zuern v. Ford Motor Co.,
BACKGROUND
¶ 2 We view the evidence in the light most favorable to upholding the jury verdict. Hutcherson v. City of Phoenix,
¶ 3 Pandhi, possibly after having fallen asleep at the wheel, lost contrоl of the vehicle as Griesmer slept. Both right wheels left the right side of the pavement, prompting Pandhi to rapidly steer to his left and then back to the right when the vehicle reached the roadway’s left shoulder. The vehicle went off the left side of the road and rolled over five and one-half times. Plaintiff presented evidence, albeit disputed, that the vehicle’s roof header and A-pillar above Griesmer’s head collapsed inward onto her skull during the rollover, causing permanent and totally disabling closed head injuries.
¶ 4 Griesmer’s mother/conservator, plaintiff Carol Larsen, filed this action against Nissan, alleging negligent design and strict product liability for design and manufacturing defects. Plaintiff did not name Pandhi as a defendant because, as Griesmer’s employer, he was immune from liability pursuant to A.R.S. § 23-906(A). Nissan, however, named Pandhi as a nonparty at fault pursuant to A.R.S. § 12-2506(B) and Rule 26(b)(5), Ariz. R. Civ. P., 16 A.R.S. After a lengthy trial, the jury returned a vеrdict in plaintiffs favor but allocated 92 percent of the fault to Pandhi and the remaining eight percent to Nissan. This appeal followed the trial court’s entry of judgment on the verdict.
DISCUSSION
A. Application of A.R.S. § 12-2506
¶ 5 Under the Uniform Contribution Among Tortfeasors Act (UCATA), A.R.S. §§ 12-2501 to 12-2509, “each tortfeasor in a personal injury action is liable only for his or her share of fault.” Sanchez v. City of Tucson,
¶ 6 Based on the applicable case law, plaintiff apparently concedes that A.R.S. § 12-2506 “establish[es] a system of several liability making each tortfeasor responsible for paying for his or her percentage of fault and no more.” Dietz,
¶ 7 Similar to plaintiffs argument here, the appellants in Zuem contended that “the only relevant consideration bearing on fault was the extent to which [plaintiffs] injuries were caused by the design of the [vehicle] and the extent to which they were caused by the foreseeable collision.” Id. at 490,
We disagree with plaintiffs’ contention that the comparative fault issue should have been limited to “the extent to which the collision or defects in the [vehicle] cаused or contributed to [plaintiffs] injuries or damages.” Section 12-2506(0 requires the trier to assess “degrees of fault,” not just degrees of causation. Although causation (or physical contribution to the injury) is a necessary condition precedent to consideration of a person’s fault — i.e., the fault must have “proximately caus[ed] or contributed]” to the claimant’s injuries to be considered, A.R.S. § 12-2506(F)(2) — once causation is found the trier of fact must determine and apportion “the relative degrees of fault” of all parties and nonparties. § 12-2506(C).
Id. at 491-92,
¶ 8 Plaintiff urges us to reexamine Zuem which, she asserts, should be overruled or modified. We decline to do so for two reasons. First, we believe the holding in Zuem is consistent with, and indeed required by, the clear language of § 12-2506.
¶ 9 Addressing the impact of UCATA on Holtz, the court in Piner concluded that “the present version of UCATA has left intact the rule of indivisible injury, relieving the plaintiff of apportioning damage according to causal contribution.”
The second part of the Holtz rule, however, was abrogated by § 12-2506(A). Contrary to the common law and cases such as Gehres [v. City of Phoenix,156 Ariz. 484 ,753 P.2d 174 (App.1987) ], the fault of all actors is compаred and each defendant is severally liable for damages allocated “in direct proportion to that defendant’s percentage of fault.” § 12-2506(A). To determine each defendant’s liability “the trier of fact shall multiply the total amount of damages recoverable by the plaintiff by the percentage of each defendant’s fault, and that amount is the maximum recoverable against the defendant.” Id.
Thus in an indivisible injury ease, the factfindеr is to compute the total amount of damage sustained by the plaintiff and the percentage of fault of each tortfeasor. Multiplying the first figure by the second gives the maximum recoverable against each tortfeasor. This result conforms not only with the intent of the legislature and the text of the statute but also with common sense. When damages cannot be apportioned between multiple tortfeasors, there is no reason why those whose conduct produced successive but indivisible injuries should be treated differently from those whose independent conduct caused injury in a single accident....
¶ 10 In addition to the controlling precedent against her, plaintiffs focus on causation as the sole determinant of responsibility for damages is misplaced because the causation element is factored in as “a necessary condition precedent to consideration of a person’s fault” under a comparative fault system like Arizona’s. See Zuern,
There is some debate over what is to be compared under comparative negligence, negligence or causation. The prоblem in certain respects is one of terminology. Causation in fact is an absolute concept, which by its nature is incapable of being divided into comparative degrees — it either exists or it does not. The adoption of comparative negligence, therefore, should not affect this preliminary determination.
W. Page Keeton et al., Prosser and Keeton on the Law of Torts § 67 at 474 (5th ed.1984). Thus, apportionment of causation would be difficult if not impossible. In contrast, there is “no doubt that jurors are capable of evaluating degrees of fault, and the statute reflects our legislature’s agreement.” Hutcherson,
B. Constitutionality
¶ 11 Plaintiff also argues that the statute violates article 2, § 31 of the Arizona Constitution, which provides: “No law shall be enacted in this State limiting the amount of damages to be recovered for causing the
¶ 12 We first note, and plaintiff acknowledges, that the constitutional issue “was not discussed by the parties before the trial court.” Nor did plaintiff request a jury instruction or form of verdict calling for assessment of damages based on apportionment of causation rather than allocation of fault, ostensibly because of Zuem. Although appellate courts generally do not consider issues not raised in the trial court, that rule is procedural rather than jurisdictional. See Cutter Aviation, Inc. v. Arizona Dep’t of Revenue,
¶ 13 As we recently recognized: “Statutes are presumed to be constitutional, and the party asserting that a statute is unconstitutional has the burden of clearly demonstrating that it is. If possible, we construe a statute so as to avoid rendering it unconstitutional, resolving any doubts in favor of its constitutionality.” Ramirez v. Health Partners of Southern Arizona,
¶ 15 Although our supreme court in Dietz permitted defendants to name the plaintiffs immune employer as a nonparty at fault, the court did not “view the [worker’s compensation] lien provisions as a limitation on the amount of damages recoverable and [found] no violation of article 2, § 31.” Dietz,
¶ 16 Plaintiff does not challenge those cases which, as she correctly notes, did not squarely address the specific constitutional argument she prеsents here.
¶ 17 The legislative abolition of joint and several liability in 1987 clearly may result in a plaintiff receiving less damages from a defendant who “caus[ed] the death or injury,” article 2, § 31, than the plaintiff potentially would have received under prior Arizona law. Compare Church with Gehres. For example, in Church, the jury found that Rawson’s negligence was a cause of plaintiffs injury, but her net recovery against Rawson was only $17,541.83 (one-third of the totаl damage award), instead of the $35,083.66
¶ 18 Plaintiff contends, somewhat persuasively, that the statutory framework for assessing damages based strictly оn fault allocation is bad policy and unfairly limits plaintiffs’ recovery.
¶ 19 As a comparison, of Zuem and Hutcherson illustrates, however, the statutory allocation of fault system does not necessarily favor plaintiffs or defendants. Rather, the system permits jurors to evaluate all the evidence, including facts bearing on causation, and allocate fault based on the jurors’ collective concept of what is fair.
DISPOSITION
¶20 The trial court’s judgment is affirmed.
Notes
. In a separate memorandum decision, we also reject plaintiff’s alternative assertions that she is entitled to a new trial because of Nissan’s disclosure violations and the trial court's alleged erroneous evidentiary rulings. The issues addressed in that decision do not warrant publication. See Rule 28(g), Ariz. R. Civ.App. P., 17B A.R.S.; Fenn v. Fenn,
. The Arizona Supreme Court dismissed a petition for review as having been improvidently granted in Zuern, and also denied a motion to depublish this court’s opinion. Zuern v. Ford Motor Co.,
. We also question plaintiff’s stаnding to raise the constitutional issue, inasmuch as her recovery of damages arguably was limited, if at all, by Arizona’s constitutionally-based workers’ compensation scheme and by Nissan’s ability to name Griesmer’s employer as a nonparty at fault. Because standing is not a constitutional jurisdictional requirement in Arizona and Nissan waived the issue by not raising it on appeal, we consider plaintiff's constitutional argument on the merits. See State v. B Bar Enterprises, Inc.,
. In Smith, the court held that "Arizona’s periodic payment scheme [under A.R.S. §§ 12-581 to 12-594, applicable only to medical malpractice cases] is effectively a damage limitation prohibited by Ariz. Const. art. 2, § 31.”
. Plaintiff asserts that the dichotomy between legislative “regulation” and "abrogation,” discussed extensively in cases that have analyzed article 18, § 6 of the constitution, “is neither required nor helpful here.” See, e.g., Jimenez, Hazine v. Montgomery Elevator Co.,
. One commentator has suggested that article 2, § 31 would preclude the legislature from arbitrarily limiting the amount of damages recoverable in a recognized cause of action, but might not prohibit it from "substituting] a reasonable compensation system, for example a no-fault insurance system for auto accidents, for certаin types of tort actions as long as there were no other constitutional impediments.” Roger C. Henderson, Tort Reform, Separation of Powers, and the Arizona Constitutional Convention of 1910, 35 Ariz. L.Rev. 535, 618-19 n. 713 (1993).
. Contrary to Nissan's assertion, Zuern did not address any constitutional issues at all.
. We note that the parties stipulated, and the jury was informed, that "Kimberly Griesmer's medical bills have been and will be paid by the Arizona State Workers Compensation Fund,” that plaintiff could not sue Pandhi, and that any repayment of medical benefits to the State Cоmpensation Fund would "be reduced by the percentage of fault found against Dr. Pandhi.” See Aitken v. Industrial Commission,
. This court has recognized that "the comparative fault statute apportiоns fault, even at the expense of the plaintiff." Rosner v. Denim & Diamonds, Inc.,
. "Guiding this statutory revision was a desire to 'increase the fairness of the tort system for both plaintiffs and defendants’ by making each tortfeasor liable for only his or her share of fault, and no more.” Hutcherson,
. As our supreme court has stated: ”[T]he regime adopted to determine several liability is [not] part of the common law system of this state. [It is], instead, [a] creature[] of the legislature. Consequently, absent a constitutional violation, resolution of this problem must come from interpretation of the statutes.” Dietz,
