By age 9 the percentage of players participating on at least two teams increased from 21.2 % to 47.1 % .
Average total games played per year increased from 34.55 to 60.35 .
By age 9 the percentage of players participating on at least two teams increased from 21.2 % to 47.1 % , and average total games played per year increased from 34.55 to 60.35 .