With the introduction of the new merit points system in addition to activity, leveling up is now impossible to predict. I still like your spreadsheet and I'm keeping it in my bookmarks, but man... what a bummer.
For those who missed the news:
https://bitcointalk.org/index.php?topic=2818350.0What do you guys think about merits?
I think this is one solution to all the spam here. It's easy to reach 10 Merit points if you post quality posts. From 10 to 100 is a bit more difficult for Full member. We are still in the beginnig of the new system, hope that with the time the system will be adjusted. Lets see what happens from now on.