Summary statistics for aorticmitralvalvereplacementper1 variable in 2007_surg_d Variable | Obs Mean Std. Dev. Min Max -------------+--------------------------------------------------------- aorticmitr~1 | 1,009 -.660984 1.54779 -5.173067 3.152825 by Jean Roth , jroth@nber.org , 14 Mar 2018