In tumbling, athletes perform an explosive series of flips and twists down a sprung tumbling track. Scoring is similar to trampolining. Tumbling was originally contested as one of the events in Men's Artistic Gymnastics at the 1932 Summer Olympics, and in 1955 and 1959 at the Pan American Games. From 1974 to 1998 it was included as an event for both genders at the Acrobatic Gymnastics World Championships. The event has also been contested since 1976 at the Trampoline World Championships. Since the recognition of Trampoline and Acrobatic Gymnastics as FIG disciplines in 1999, official Tumbling competitions are only allowed as an event in Trampoline gymnastics meets.
What year did the Trampoline Championships begin?