Level Cap Increasing/Stat Improvement

First, 10% is not how that works, at all.

However, let's accept your 10% more than the last level argument. Now, let's assume the amount of XP needed to go from level 1 to 2 is our fundamental unit.

The total number of units to go from level 1 to 85 is 29981.

The amount of time it takes to go from level 1 to 85 is about five months, as a rule of thumb.

Now.

Continue that 10% pattern out to level 90. That's 18310 units, or about 3 months to go from level 85 to 90.

Continuing that 10% pattern out to level 100, that's an additional 76978 units, or about twelve months, to go from level 90 to 100.

However, the actual scaling for XP and level gain does not have a unifying fixed pattern like "10% more," and is set in a more manual, setpwise fashion, such that we can't actually speculate on how long it would take to level up.