The list was composed off all the martial artists that participated in Tenkaichi Budokai's for the past 10 years, so that comprises 3 tournaments: 22nd, three years before 21st and five years before 20th. That, off course, makes seven years, and 19nt was five years before 20th so it could not be in the list.
Thus I conclude that Akkuman won the 20th Tenkaichi Budokai. But them I realized that King Chapa was on that list as well, so before someone poses the question, this is what I concluded: King Chapa participated in that tournament and probably lost against Akkuman. The tournament King Chapa won could be the 19nt, but that's just speculation.
Thoughts? Did I miss something?
I'm just putting this here because this kind of questions arose in some other topic some time ago.