Frequencies for first 10,000 rows of retprn variable in nhamcsopd2008 dataset :

 return prn |      Freq.     Percent        Cum.
------------+-----------------------------------
         no |      7,662       76.62       76.62
        yes |      2,338       23.38      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 28 Mar 2016