Level 1-2 is 1 day
2-3 is 4 days
3-4 is 9 days
4-5 is 16 days
5-6 is 25 days
6-7 is 36 days
7-8 is 49 days
8-9 is 64 days
So i can conclude 9-10 is 81 days. So nearly 3 months
Quite a nice pattern going on there...
Seems as if it will go to 100 days, 121 days, 144 days, 169 days... and so on! Not that anyone will likely get there!