Frequencies for first 10,000 rows of psa variable in namcs2007 dataset :

   psa test |      Freq.     Percent        Cum.
------------+-----------------------------------
         no |      9,793       97.93       97.93
        yes |        207        2.07      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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