Cohort progression — Team England
Median season-best times of each birth-year cohort, overlaid by age — shows how consecutive groups developed at the same stage of training.
Event: 100 freestyle200 medley200 freestyle100 butterfly100 backstroke50 freestyle400 freestyle50 butterfly200 backstroke200 butterfly50 backstroke200 breaststroke100 breaststroke400 medley800 freestyle50 breaststroke1500 freestyle