My two cents. Trials bikes in the USA has always gone in spurts. Unfortunately always too low of numbers. 75-76 was good. 82-83. (SWM, Fantics) 1985 was cool with disc brakes and mono. 91-92. 95-96 were good years. `98 the 315 was killer. 2001 all bikes jumped ahead. 2005-2006 were good. Pretty much down hill from there, due to price and small numbers!
Just too many models, FOR SUCH A LIMITED sport!
If I was a betting man, I would say 1995 was the best year!