Sixty-three percent of Wyoming's public school students in kindergarten through third grades are in classes exceeding the state's new student-to-teacher ratio.

Wyoming Education Department data obtained by the Associated Press shows that 20 of 48 school districts don't meet the mandated average class size of 16-to-1 in the early grades. In general, the largest school districts have the most difficult time meeting the ratio.

State Schools Superintendent Cindy Hill says districts are doing what they can to meet the ratio. She says she's confident all districts eventually will meet the standard set by the 2011 legislature as part of its education reform.

Hill says districts can seek a waiver from the education department if they show good reason why they can't meet the standard.