I believe it first appeared in PT57. Here is the list by PowerScore up until 2016: http://www.powerscore.com/gamesbible/logic-games-rule-substitution/index.cfm
(June 2009 LSAT = PT57)
@LSATcantwin @"surfy surf" I decided not to apply to UC Hastings after reading about the Tenderloin area....(http://m.sfgate.com/local/article/Theater-star-leaving-SF-writes-open-letter-12219346.php ) I think I made the right decision...