Summary statistics for mdcl_scl_workr_vlntr_cnt variable in pos2009 dataset :

    Variable |        Obs        Mean    Std. Dev.       Min        Max
-------------+---------------------------------------------------------
mdcl_~tr_cnt |    122,973    .0025481    .1509925          0         28

by Jean Roth , jroth@nber.org , 17 May 2017