PCAT percentile ranks are based on the performance of the current normative sample—all first- time PCAT candidates from June 2007 through January 2011 (n = 68,241). However, percentile ranks obtained prior to July 2012 were based on the performance of the previous normative sample—all first-time PCAT candidates from October 2004 through May 2007. For this reason, the current percentile ranks are not directly comparable to previously earned percentile ranks.