Summary statistics for drg2mdcxw1993 dataset : by Jean Roth , jroth@nber.org , 22 Apr 2016 Variable | Obs Mean Std. Dev. Min Max -------------+--------------------------------------------------------- drg | 0 drgnum | 491 246.9328 142.422 1 494 mdc | 491 9.1222 6.071793 0 25 drgdesc | 0 mdcdesc | 0 by Jean Roth , jroth@nber.org , 22 Apr 2016