Version release dates

I know the release dates for gmod 10 and 13 was on Nov 29, 2006 and Sep 24, 2012.

But when was gmod 11 and 12 released? It’s okay if you only remember the years and not the months.

'After some research, I conclude that GMOD 11 was probably released in January 2009 as a mod for the Source SDK 2006 and GMOD 12 maybe in June 2010.

Interesting discoveries during my research: