According to my Wallet, I am receiving .001 SP per minute on 280 Steem Power
.001 SP/minute * 60 minutes/hour * 24 hours/day * 365 days/year = 525.6 Steem Power/year
Interest Earned / Starting balance = Interest Rate
Therefore,
525.6 / 280 = 1.877 ( multiply by 100 to turn into a percentage) and....
Interest Rate = 187% per year
I'm assuming I'm not calculating an important figure...
Or is this math correct?