Summary statistics for partdpremiumobligationwith50prem variable in planreport2012 dataset :

    Variable |        Obs        Mean    Std. Dev.       Min        Max
-------------+---------------------------------------------------------
partdp~0prem |    156,934    22.01344    56.22967          0       1233

by Jean Roth , jroth@nber.org , 14 Apr 2016