 Single-sex schools are deemed to have double their actual average enrollment for cross-country and track; prior to the 2007 realignment, football also used this rule.In cross-country and track, the KHSAA rule is to divide the classes so that 40% of all schools that sponsor the sport are in Class A and 30% are in both Class AA and AAA.As is standard for high school sports in the U.S., students are limited to four consecutive years of eligibility (grades 9-12), whether or not they participate in any sports during one or more of those years.