Grant, J.

(after stating the facts). The learned counsel for the respondent contends;

*6711. That the law includes passenger fares alone, and excludes earnings for the transportation of express and mails.

2. That the statute is void, as a state regulation of interstate commerce.

The language, “the gross earnings of whose passenger trains,” standing by itself, is susceptible of but one construction. A passenger train consists of its passenger, baggage, express, and mail cars. It would do violence to the plainest rules of construction to hold that its gross earnings did not include the receipts from each source of income. The language is too plain to be changed by other expressions of the statute to which this act was an amendment, or by the subsequent term, “passenger earnings,” used in the act itself in the provision for roads in the Upper Peninsula. There would be some force in holding that the former controls the latter, but we are unable to see any force in the claim that the latter controls the former. A similar attempt was made to thus change the express language of a statute in Connecticut Mut. Life Ins. Co. v. Wood, 115 Mich. 444 (74 N. W. 656), but we held that it could not prevail.

Two other facts tend strongly to sustain this construction, and to show the intent of the legislature in using this language: (1) Contemporaneous construction. Immediately after the passage of the act, both the railroad companies and the railroad commissioner adopted this construction. These items were included in the amount upon which the Grand Trunk Railway was compelled to reduce its fare to 2 cents per mile. Wellman v. Railway Co., 83 Mich. 592 (47 N. W. 489), 143 U. S. 339 (12 Sup. Ct. 400). Evidently the officers of the road so interpreted the law, or they would have contested the case on that ground. Other like instances will be found in the reports of the railroad commissioner. (2) For a number of years prior to the passage of the act, railroad earnings were reported under two heads, “Passenger Earnings” and “Freight Earnings.” In the former were included earn*672ingsfrom “ passenger fares, express, baggage, and mails.” Courts will assume that the legislature was familiar with those reports, and used the term “earnings from passenger trains ” with the meaning that had thus been given to it. We think the court below erred in its holding.

The report filed by respondent, and upon which the order of the commissioner is based, is marked, “Analysis of Income in the State of Michigan — Passenger Income.” Then follow the figures above given. It is the established rule that States may regulate fares of railroads within their territory, based upon their domestic commerce. State Freight Tax Case, 15 Wall. 232; Louisville, etc., R. Co. v. Railroad Commission of Tennessee, 19 Fed. 679; Wabash, etc., R. Co. v. Illinois, 118 U. S. 557, 564 (7 Sup. Ct. 4); Carton & Co. v. Railroad Co., 59 Iowa, 148 (13 N. W. 67, 44 Am. Rep. 672). This statute can be held to include only domestic commerce, and is therefore valid. On the face of the report, only domestic earnings are included. Respondent, in its answer, alleges that the “$141,922 reported by the respondent as aforesaid includes, not only its receipts from passenger fares between points in Michigan (that is to say, way or local fares), but also includes an aliquot or proportionate part for Michigan of receipts from passenger fares between points in Ohio, Indiana, Illinois, Missouri, Michigan, and Canada (that is to say, through or interstate fares).” But it has failed to show the amount of such interstate fares earned in Michigan. It is not, therefore, in position to raise this question, since the burden of proof was upon it to show that it had erroneously included sufficient items coming within the rule of interstate commerce to reduce its earnings below $2,000 per mile. We are not, therefore, called upon to decide whether such earnings can be included in the computation.

Judgment reversed, and entered in this court for the relator.

The other Justices concurred.