Frequencies for first 10,000 rows of sex variable in demo2004q1 dataset :

   Code for |
  patient's |
        sex |      Freq.     Percent        Cum.
------------+-----------------------------------
            |        480        4.80        4.80
          F |      5,079       50.79       55.59
          M |      4,354       43.54       99.13
         NS |         18        0.18       99.31
        UNK |         69        0.69      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 18 Dec 2015