 Complete the following phrase:  There have been several milestones in the Paralympic movement. The first official Paralympic Games, coincident with the ninth Stoke Mandeville Games but no longer open solely to war veterans, was held in Rome in 1960. 400 athletes from 23 countries competed at the 1960 Games. Since 1960, the Paralympic Games have taken place in the same year as the Olympic Games. The Games were initially open only to athletes in wheelchairs; at the 1976 Summer Games, athletes with different disabilities were included for the first time at a Summer Paralympics. With the inclusion of more disability classifications the 1976 Summer Games expanded to 1,600 athletes from 40 countries. The 