Seventy-Two Inc., a developer of radiology equipment, has stock outstanding as follows: 80,000 shares of cumulative preferred 3% stock, $20 par and 400,000 shares of $25 par common. During its first four years of operations, the following amounts were distributed as dividends: first year, $36,000; second year, $72,000; third year, $80,000; fourth year, $100,000. Determine the dividends per share on each class of stock for each of the four years?