Summary statistics for pspp2009_60 dataset : by Jean Roth , jroth@nber.org , 12 Feb 2018 Variable | Obs Mean Std. Dev. Min Max -------------+--------------------------------------------------------- npi1 | 0 npi2 | 0 paircount | 67,915,893 203.0289 723.0374 11 336565 benecount | 67,915,893 42.87279 100.2701 11 67672 samedaycount | 67,915,893 15.05537 120.7825 0 165965 -------------+--------------------------------------------------------- year | 67,915,893 2009 0 2009 2009 days | 67,915,893 60 0 60 60 begdate | 67,915,893 17898 0 17898 17898 enddate | 67,915,893 18322 0 18322 18322 by Jean Roth , jroth@nber.org , 12 Feb 2018