I'm trying to decide which Android version has which support period and lifetime.
All Android versions have "support", to the same extent that all Debian versions that have ever been created have "support". Anyone can, with sufficient work, run whatever Android version they want, just as anyone, with sufficient work, can run any Debian version they want.
All that matters is what versions you want to support. You will make that choice, yourself, based on whether or not you think there are enough users of a given Android version to make the incremental maintenance cost worthwhile. To help you make that determination, Google publishes a chart and table of the percentage of Android devices running each significant version.

At the time of this writing, some developers are dropping support for Android 1.x entirely, since combined they represent 1.2% of the user base. However, that is their decision, and you have to make yours.