From 1920 to 1934, the NFL did not have a set number of games for teams to play, instead setting a minimum. The league mandated a 12-game regular season for each team beginning in 1935, later shortening this to 11 games in 1937 and 10 games in 1943, mainly due to World War II. After the war ended, the number of games returned to 11 games in 1946 and to 12 in 1947. The NFL went to a 14-game schedule in 1961, which it retained until switching to the current 16-game schedule in 1978. Proposals to increase the regular season to 18 games have been made, but have been rejected in labor negotiations with the National Football League Players Association (NFLPA).