Own the series but cannot find out how old Jax was when his dad died

He was born in 1940 and died in 1993, so he would have been 52 o 53, depending on what mes he died. Also, my dad was also born in 1940 and died in 1993.

JT died in 1993, and Jax was born in 1978, so
1993-1978= Jax was 15.