Scotty was born in 2222. He was 43 at the beginning of the 5 year mission. He was 63 when Kahn captured the Reliant to attack the Enterprise. He was 64 when Captain Kirk was pulled into the Nexus. When he was 72, he was trapped in a transporter loop on the USS Jenolan. He wasn't rescued until 2369 - the last time we saw him. That means, it was 147 years since his birth, but he had only really lived 72 of those.