Summary statistics for asc_bgn_srvc_dt variable in pos2011 dataset :

    Variable |        Obs        Mean    Std. Dev.       Min        Max
-------------+---------------------------------------------------------
asc_bgn_sr~t |      6,955    14277.81    2970.607     -27140      18947

by Jean Roth , jroth@nber.org , 20 Apr 2019