Frequencies for first 10,000 rows of psa variable in nhamcsopd2006 dataset :

   psa test |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      9,910       99.10       99.10
        Yes |         90        0.90      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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