Summary statistics for numdiffphyspdeceol variable in daphrr2009 dataset :

    Variable |        Obs        Mean    Std. Dev.       Min        Max
-------------+---------------------------------------------------------
numdiffphy~l |        307    9.115966    1.939904   5.279545   14.42362

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