For the last 10 years I calculated a 63% compounding interest. Still unbeated by any other investment.

(To calculate compound interest, use the formula: A = P(1 + r/n)^(nt), where A is the total amount, P is the principal amount, r is the annual interest rate (as a decimal), n is the number of times interest is compounded per year, and t is the number of years. )