The cash prizes for two six-month and one-year treasury bills are $ 93 and $ 90, respectively. A 1.5 year bond that pays a coupon of $ 5 is currently selling for $ 97. A 2-year bond that pays a coupon of $ 6 is currently selling for $ 99. Based on this information, calculate the 6-month, 1-year, 1.5-year and 2-year spot rates?