Since 1964, under the holding of "Reynolds v. Sims", 377 U.S. 533 (1964) districts must be apportioned within a 5% margin of the average target size district as determined by the U.S. Census state population figures divided by the forty-eight districts. This allows for some districts to be slightly smaller or larger than others. The Oklahoma Senate draws its own maps of its district lines, which are subject to the approval of both the Oklahoma House of Representatives and the governor. Should the redistricting not occur in a timely manner, the lines are determined by a panel of five statewide elected officials.