ericpfeifer-izenda June 26, 2017:  Updated Custom Aggregate Functions (markdown) [07177fd]
Joseph Adams February 21, 2017:  Updated Custom Aggregate Functions (markdown) [0c8996d]
Joseph Adams February 21, 2017:  Updated Custom Aggregate Functions (markdown) [e0ab139]
Joseph Adams September 28, 2016:  Updated Custom Aggregate Functions (markdown) [398450d]
Joseph Adams May 12, 2014:  Updated Custom Aggregate Functions (markdown) [ea489d9]
Joseph Adams May 12, 2014:  Created Custom Aggregate Functions (markdown) [8cf29de]