The 1907 championship featured eleven teams, with each team playing the other twice.
The championships featured only a senior men's race from 1903 to 1961, at which point an under-21s event was introduced.
The championships featured six races: there were senior, under-23, and under-20 junior categories for each of the sexes.
The 1909 championship featured 10 teams, with each team playing the other twice.
The championships feature an individual event and a six-person team event.
The 2011 championship will feature a new format.
These championships will feature swimming events in a 25-meter (short-course) pool.
This year, for the first time, the championship featured a group stage play-off system.
On top of these events, the championship also features many side events that do not impact the match aggregate score.
The 1911 championship featured 9 teams, with each team playing the other twice.