Your math is wrong, you currently have 82876499 in your wallet and you started with 81474800.  This is 1.72%.  So you don't have to worry about your 13% interest going anywhere.

Assuming you bought at the lowest in the month of february @21 satoshis per mint, it was worth about 17.1 BTC.
The current price of .12 (you could argue .11) satoshis with 82876499 is worth about 9.95BTC.

We won't even factor in the drop in BTC.

If everyone is getting rich off the interest, where is the money coming from?  Of course it would be true in this case if we were still at 21 satoshis, but everytime we fall a point, it hurts more then any interest you can gain.  A fall from 13 to 12 is 8.3% loss in what your mint is worth.

It's only a matter of time before people realize the price isn't going to go up take their losses and re-invest into coins that are rising and try to make up some of those losses.