The correct answer is 85%
Between 1975 and 2013 the Texas legislature proposed 299 amendments for voter approval, and of these, voters accepted 85% percent.
Article XVII, Section 1 of the Constitution of 1876 states that two-thirds of the representatives of ten Texan legislature can propose amendments during the session, specifying the dates to be submitted to the voters in the state. The Texan legislature has to publish the amendment in public newspapers fifty days before the election.