Investigation of the historical structure changes of the sumo world using the statistical-analysis result of the Banzuke

1981-2000年入队的相扑选手活跃期平均为6.12年，但大多数在第2年就退出了。如果仅限于经历过“关取”的摔跤手，它可以用一个类似于正态分布的直方图来表示，平均值的峰值为14.64年。但是在Makushita以下的班级里，有几个摔跤手作为活跃的摔跤手的时间比这长。这包含一个角色摔跤手服务员，谁被要求作为积极的摔跤手。

The average of the active period of the sumo wrestlers who entered in 1981-2000 is 6.12 years, but most of all resigned by the 2nd year. If limited to the wrestlers experienced 'Sekitori', it can express with a histogram similar to the normal distribution with a peak of average value (14.64 years).In relation with a status, the active period is 16 years at the longest who experienced the Yokozuna. But a few wrestlers act as active wrestler longer than this in the class below Makushita. This contains a role wrestler attendant, who is requested to act as active wrestler.