If you were born on Monday, September 09, 1940 then Rhinestone Cowboy by Glen Campbell was the number one on your 35th birthday, and went to number one on August 31, 1975. Check the price of Rhinestone Cowboy by Glen Campbell on Amazon.com
The biggest selling book of 1975 (the year you turned 35) was Ragtime by E.L. Doctorow.