The average stock on the S&P 500 trades at 16 times earnings (P/E). This means that the stock price divided by the expected earnings per share (EPS) over the next 12 months is equal to 16. Assume that the average stock has a payout ratio of 50% and has expected earnings per share over the next 12 months of $1. If the average S&P 500 stock has an expected rate of return of 9% and is priced as a growing perpetuity, what average annual dividend growth rate is the market estimating?