Frequencies for first 10,000 rows of psa variable in nhamcsopd2011 dataset :

        PSA |
  (prostate |
   specific |
   antigen) |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      9,886       98.86       98.86
        Yes |        114        1.14      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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