Summary statistics for icd2ccrxhcc1xw2009 dataset : by Jean Roth , jroth@nber.org , 12 Jan 2016 Variable | Obs Mean Std. Dev. Min Max -------------+--------------------------------------------------------- icd | 0 cc | 0 icdvers | 3,191 9 0 9 9 modtype | 0 modvers | 3,191 1 0 1 1 -------------+--------------------------------------------------------- year | 3,191 2009 0 2009 2009 by Jean Roth , jroth@nber.org , 12 Jan 2016