Release dates of Debian and Support times

[Rajkumar S]

Hi,

I am doing a comparative study of support times of various OS.  So I 
would like to know when various stable releases were released and for 
how long were they supported? MS and Redhat has released their plans at

http://www.redhat.com/apps/support/errata/rhlas_errata_policy.html
http://support.microsoft.com/default.aspx?scid=fh;[ln];LifeWin

I know that Debian development process is not tuned for release dates 
and such, but these are the information about Debian I am looking for.

raj