Complex sentence: Bullock held the comptroller's office from 1975--1991, when he was easily elected to succeed retiring Lieutenant Governor William P. "Bill" Hobby, Jr., of a prominent Houston family.
Split into simpler sentences: Bullock held the comptroller's office from 1975--1991. In 1990, he was easily elected to succeed retiring Lieutenant Governor William P. "Bill" Hobby, Jr., of a prominent Houston family.