Pecan Theatre Inc. owns and operates movie theaters throughout Florida and Georgia. Pecan Theatre has declared the following annual dividends over a six-year period: 20Y1, $80,000; 20Y2, $90,000; 20Y3, $150,000; 20Y4, $150,000; 20Y5, $160,000; and 20Y6, $180,000. During the entire period ended December 31 of each year, the outstanding stock of the company was composed of 250,000 shares of cumulative, preferred 2% stock, $20 par, and 500,000 shares of common stock, $15 par. Assuming a market price per share of $25.00 for the preferred stock and $17.50 for the common stock, determine the average annual percentage return on initial shareholders' investment, based on the average annual dividend per share (a) for preferred stock and (b) for common stock.