We are looking at a market with 520M items in 2012 and want to know how big it will be in 2015. We know that growth rate from 2011-2012 was 4.7% and can assume the same for the next three years. I see here the result is 602M, so the 520M was multiplied by 1.05(to the power of three), but don't know why. What is the formula you use to calculate growth like this?

Thank you.