Summary statistics for pspp2009_30 dataset : by Jean Roth , jroth@nber.org , 12 Feb 2018 Variable | Obs Mean Std. Dev. Min Max -------------+--------------------------------------------------------- npi1 | 0 npi2 | 0 paircount | 50,382,951 153.597 487.9307 11 204166 benecount | 50,382,951 42.19798 95.17179 11 63446 samedaycount | 50,382,951 18.56049 130.9472 0 153957 -------------+--------------------------------------------------------- year | 50,382,951 2009 0 2009 2009 days | 50,382,951 30 0 30 30 begdate | 50,382,951 17898 0 17898 17898 enddate | 50,382,951 18294 0 18294 18294 by Jean Roth , jroth@nber.org , 12 Feb 2018