Question: When did the conference the UNLV Runnin' Rebels are a member of begin operations?
Sentence (from "1989–90 UNLV Runnin' Rebels basketball team"): As of the present, they are the last team from any of the non-big six conferences (ACC, Big East, Big Ten, Big 12, Pac-10, and SEC) to win the national championship.
Relevant evidence: No