I couldn’t verify an exact Android version list specifically for September 2019 through March 2020 from the sources available, but the public version histories I found show that the commonly listed Android builds around that era include 1.5.x and 1.6.x , with older-version pages explicitly listing 1.5.2, 1.5.9, 1.5.11, 1.5.13, 1.6.5, 1.6.6, 1.6.7, 1.6.8, and 1.7.1.

What’s visible in the history

The version-history pages I found do not give a clean month-by-month release log for 2019–2020, but they do show these older Android releases as available download versions.

Version| Shown in source| Notes
---|---|---
1.5.2| Yes 10| Older APK listed on version archive pages.
1.5.9| Yes 10| Older APK listed on version archive pages.
1.5.11| Yes 110| Older APK listed on version archive pages.
1.5.13| Yes 110| Older APK listed on version archive pages.
1.6.5| Yes 10| Older APK listed on version archive pages.
1.6.6| Yes 110| Older APK listed on version archive pages.
1.6.7| Yes 110| Older APK listed on version archive pages.
1.6.8| Yes 110| Older APK listed on version archive pages.
1.7.1| Yes 110| Older APK listed on version archive pages.

Practical read

If you’re trying to identify the Android builds from that time window , the safest answer from the available public archives is that Tank Stars’ 2019–early 2020 era is most likely in the 1.5.x to 1.7.1 range , with exact month-to-version mapping not fully shown in the accessible listings.

TL;DR

The Android versions most clearly surfaced by the archives for that older period are 1.5.2, 1.5.9, 1.5.11, 1.5.13, 1.6.5, 1.6.6, 1.6.7, 1.6.8, and 1.7.1.