OPINION
T1 Erich Ross Diener appeals from the trial court's denial of his motion to modify his child support obligation. We affirm in part and remand for additional findings.
BACKGROUND
12 On April 17, 1998, Erich Ross Diener (Father) and Tiffany Jacobs Diener (Mother) were divorced through a stipulated decree. Mother was granted physical custody of the sole child born to the couple. Although Father's income was approximately $1,700.00 per month, and Mother's was approximately $1,200.00 per month, Father agreed to pay child support in the amount of $400.00 per month, an amount that exceeded the amount required under the Utah Child Support Guidelines (the Guidelines). See Utah Code Ann. § 78-45-7.14 (2002). 1
1 3 In December 2001, Father filed a petition with the trial court seeking to modify the amount of his child support obligation pursuant to Utah Code sections 78-45-7.2(6) and (7). 2 Father argued first that modification was justified because he had experienced substantial material changes in his cireum-stances following the divorce. He also argued that the amount he had agreed to pay was outside of the acceptable deviation range permitted by statute and that therefore the trial court was duty-bound to modify the child support order. On March 25, 2003, after a hearing on Father's petition, the trial court issued its findings of fact and conclusions of law denying Father's attempt to modify his child support obligation. Father now appeals.
*1180 ISSUES AND STANDARD OF REVIEW
T4 Father argues that the trial court erred in denying the petition to modify his child support obligation.
"In reviewing child ... support proceedings, we accord substantial deference to the trial court's findings and give it considerable latitude in fashioning the appropriate relief." We will not disturb the district court's actions unless the court exceeded the limits of its permitted discretion. However, we review the district court's decision for correctness to the extent it involves questions of statutory interpretation.
Ball v. Peterson,
ANALYSIS
I. The Trial Court's Reliance on the Previous Agreement Between the Parties
15 Although the trial court held that Father's acceptance of the earlier stipulation provided an appropriate basis for denying his petition, and that granting Father's petition "would provide [him] with benefits of the bargain without requiring its corresponding obligations," the trial court's reasoning was incorrect. While the trial court is certainly empowered to consider the circumstances surrounding an existing stipulation when considering a petition to modify a child support obligation,
"the law was intended to give the courts power to disregard the stipulations or agreement of the parties in the first instance and enter judgment for such alimony or child support as appears reasonable, and to thereafter modify such judgments when change of circumstances justifies it, regardless of attempts of the parties to control the matter by contract."
Naylor v. Naylor,
II. Substantial Change in Cireumstances
16 Father argues that the trial court erred in finding that his financial cireum-stances had not changed substantially enough to justify modifying the child support order. We disagree.
T7 Onee a court has determined the proper amount of child support, and orders a party to pay that amount, either party may petition the court for an order modifying the amount. See Utah Code Ann. § 78-45-7.2(7)(a) (2002). However, " 'Ttlo succeed on a petition to modify ..., the moving party must first show that a substantial material change of cireumstance has occurred " 'since the entry of the decree and [second, that the change was] not contemplated in the decree itself? " '* " Boyce v. Goble,
"(i) material changes in custody; (i) material changes to the relative wealth or assets of the parties;
(iii) material changes of 80% or more in the income of a parent;
(iv) material changes in the ability of a parent to earn;
(v) material changes in the medical needs of the child; and
(vi) material changes in the legal responsibilities of either parent for the support of others."
Boyce,
8 Father argues that the trial court erred in finding that he had not suffered a substantial material change in cireumstances because "[hlis ability to earn has been substantially altered, and his earnings have been significantly decreased." Because Father's argument rests solely on his income claim, his argument turns on whether he has shown a threshold change in income of greater than 30%. See Utah Code Ann. § 78-45-7.2(7)(b)(@i) (2002). The trial court found that when the divorcee decree was entered Father was making $1,700 per month. The court then examined Father's subsequent employment history-which included a period that Father was making over $50,000 per year-and found that during the pendency of Father's petition to modify he was earning $1,277 per month from his part-time job and his monthly National Guard wage. 3 Substantial evidence was introduced at trial supporting these findings and we do not disturb them on appeal. Examining these figures, simple arithmetic shows that Father's present income level is 75.1% of his income when the decree was entered. Although a 25% drop in income is certainly a change, it does not satisfy the threshold requirement of seetion 78-45-7.2(7)(b)(Gii). Thus, as a matter of law, the changes presented in Father's petition do not qualify as a material substantial change, and they are insufficient to trigger further consideration of Father's modification petition pursuant to section 78-45-7.2(6). In the absence of any other substantive argument, we conclude that the trial court acted within its discretion in denying Father's change of cireumstances claim.
III. Section 78-45-7.2(6)
T9 Father also argues that the trial court erred in denying his petition for relief pursuant to Utah Code section- 78-45-7.2(6) (2002), because under the facts established by the trial court, the court was required to modify the existing support order. To determine the validity of Father's argument, we must first examine the requirements of seetion 78-45-7.2(6).
§10 Section 78-45-7.2(6) states:
(a) If a child support order has not been issued or modified within the previous three years, a parent ... may petition the *1182 court to adjust the amount of a child support order.
(b) Upon receiving a petition under Subsection (6)(a), the court shall, taking into account the best interests of the child, determine whether there is a difference between the amount ordered and the amount that would be required under the guidelines. If there is a difference of 10% or more and the difference is not of a temporary nature, the court shall adjust the amount to that which is provided for in the guidelines.
(c) A showing of a substantial change in cireamstances is not necessary for an adjustment under Subsection (6)(b).
(Emphasis added.) "When interpreting a statute, we look first to the plain language." Brinkerhoff v. Brinkerhoff,
Our primary goal when construing statutes is to evince "the true intent and purpose of the Legislature [as expressed through] the plain language of the Act." In doing so, we seek "to render all parts thereof relevant and meaningful," and we accordingly avoid interpretations that will render portions of a statute superfluous or inoperative.
Johansen v. Johansen,
111 The statute at issue here establishes several factors that the trial court must examine when presented with a petition to modify based upon section 78-45-7.2(6). First, the court must determine the petition, er's present adjusted gross income, as well as the respondent's present adjusted gross income, and then combine those amounts creating a combined adjusted gross income amount. Second, the court must apply the Guidelines to the combined adjusted gross income figures, see Utah Code Ann. § 78-45-7.14 (2002), to determine the amount that has been established as the presumptive support amount for the identified adjusted gross income level of the parties. Third, the court must determine proportionality, or what portion of the presumptive child support amount is attributable to the petitioner pursuant to Utah Code section 78-45-7.7. Finally, the court must determine whether the petitioner's current obligation, as set by a preexisting court order, is within ten percent (10%) of the presumptive figure arrived at through the modification petition. If there is a variance greater than 10%, the statute directs that "the court shall adjust the amount to that which is provided for in the guidelines." Utah Code Ann. § 78-45-7.2(6)(b).
112 Ordinarily, the use of the word "shall" in a statute creates a mandatory condition, eliminating any discretion on the part of the courts. See, e.g., Office of the Guardian Ad Litem v. Anderson,
1 13 Moreover, not only are statutes to be interpreted as a whole, "[wle have long ree-ognized that context is an important consideration in statutory interpretation. Because context is important, the 'terms of a statute are to be interpreted as a comprehensive whole and not in a piecemeal fashion" " Board of Educ. v. Sandy City,
[ 14 Here, the trial court found that modification would not be in the best interests of Father's child. However, as with all matters of significance in this area of the law, the trial court findings "should be more than cursory statements; they must ' "be sufficiently detailed and include enough subsidiary facts to disclose the steps by which the ultimate conclusion ... was reached." ' " Williamson v. Williamson,
CONCLUSION
15 First, the trial court acted well within its range of discretion in concluding that Father failed to show a material substantial change in cireumstances that would justify a modification of his current child support obligation pursuant to Utah Code section 78-45-7.2(7). Second, although the trial court has a degree of discretion in denying a petition to modify when the amount ordered deviates more than 10% from the amount required under the Guidelines, see Utah Code Ann. §§ 78-45-7.14; 78-45-7.2(6) (2002), such refusal must be accompanied by sufficient findings regarding the best interests of the child. Because such findings were not entered in this case; we remand this issue to the trial court for the articulation and entry of additional findings supporting its order. If, however, the trial court is unable to support its decision with such findings, we direct the trial court to examine Father's petition pursuant to the statutory requirements. If Father's current child support obligation falls outside of the permitted range, the court must then adjust Father's child support obligation pursuant to section 78-45-7.2(6).
1 16 WE CONCUR: JAMES Z. DAVIS, Judge and PAMELA T. GREENWOOD, Judge.
Notes
. Because no' significant changes have taken place in the intervening years, we refer to the most recent version of the statute unless we expressly state otherwise.
. Father's petition also sought to modify several other aspects of the divorce decree. However, the only portion of the trial court's order properly before this court involves the trial court's refusal to modify Father's child support obligation.
. The trial court made no attempt to determine whether Father was voluntarily underemployed and did not impute any income to Father. Father argues that the court's decision to forego this analysis was proper due to Father's "need" to pursue a Bachelor's degree. However, Father's reliance on his pursuit of higher education is misplaced. The pursuit of a Bachelor's degree neither excuses Father from his duty to support his child, nor does it preclude the trial court from imputing income. See Mancil v. Smith,
