Summary statistics for numdiffphyspdeceol variable in daphrr2013 dataset :

    Variable |        Obs        Mean    Std. Dev.       Min        Max
-------------+---------------------------------------------------------
numdiffphy~l |        307    9.687148    1.956329   6.009555   15.00651

by Jean Roth , jroth@nber.org , 14 Mar 2018