Summary statistics for icd9dx2007 dataset : by Jean Roth , jroth@nber.org , 27 Apr 2017 Variable | Obs Mean Std. Dev. Min Max -------------+--------------------------------------------------------- dgns_cd | 0 shortdesc | 0 version | 13,549 24 0 24 24 fyear | 13,549 2007 0 2007 2007 by Jean Roth , jroth@nber.org , 27 Apr 2017