Support lifetime for older versions

Hi,
does anyone has a link to to an overview or informations about the support end dates for older WordPress versions? I found this: http://en.wikipedia.org/wiki/WordPress#Release_history

But only the currently supported versions are listed there. I see no informations about the support endings. I want to know the latest date to update my WordPress without concerning about security.

Sometimes multiple versions ( older than the latest stable release ) seem to be supported at the same time.