Frequencies for first 10,000 rows of psa variable in namcs2012 dataset :

        PSA |
  (prostate |
   specific |
   antigen) |
       test |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      9,818       98.18       98.18
        Yes |        182        1.82      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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