Summary statistics for pspp2009_90 dataset : by Jean Roth , jroth@nber.org , 12 Feb 2018 Variable | Obs Mean Std. Dev. Min Max -------------+--------------------------------------------------------- npi1 | 0 npi2 | 0 paircount | 82,635,748 244.275 941.9208 11 474107 benecount | 82,635,748 43.71212 105.6342 11 72057 samedaycount | 82,635,748 13.50429 117.84 0 178764 -------------+--------------------------------------------------------- year | 82,635,748 2009 0 2009 2009 days | 82,635,748 90 0 90 90 begdate | 82,635,748 17898 0 17898 17898 enddate | 82,635,748 18353 0 18353 18353 by Jean Roth , jroth@nber.org , 12 Feb 2018