oops forgot to say 144 for Campag copies like Sakae Royal, Sugino, Gipiemme, Omas, Ofmega....
The changes seemed to be driven by the need to avoid duplication of gears with standard 52/42 doubles when 7-8 casetes started to arrive, henve the change to a compact crankset where a larger differential between big / small chainrings.
Shaun