Summary statistics for numdiffphyspdeceol variable in daphrr2003_2007 dataset :

    Variable |        Obs        Mean    Std. Dev.       Min        Max
-------------+---------------------------------------------------------
numdiffphy~l |        307    7.770554    1.574228   4.759859   12.34899

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