2008 TM3023 vs 2010 TM3023

I am fairly new to the forum and have learned a lot in a short amount of time. My question is this, for those looking at used TMs is there a list of major improvements that TM has made by model year? Of particular interest to me is I know what a 2010 2720 weighs on UVW but does a 2004 2720 weigh the same? It would also be helpful to know what years certain options became available or were discontinued. Just a thought.