Any schedule of rates and charges established by the commission for the transportation of passengers and freight shall, in actions brought against any railroad company involving the rates charged by the company for the transportation of any passengers or freight, or cars, including actions involving unjust discrimination in relation to such rates, be deemed and taken in all courts as sufficient evidence that the rates therein fixed are just and reasonable rates or charges for the transportation of passengers and freight and cars upon the railroads. The commission shall, from time to time, and as often as the circumstances may require, change and revise such schedules.