Cohort progression — Finland
Median season-best times of each birth-year cohort, overlaid by age — shows how consecutive groups developed at the same stage of training.
Event: 50 freestyle100 breaststroke50 backstroke50 breaststroke100 freestyle50 butterfly100 butterfly200 medley100 backstroke200 freestyle200 breaststroke400 freestyle400 medley200 butterfly200 backstroke800 freestyle1500 freestyle