Frequencies for first 10,000 rows of sex variable in demo2009q4 dataset :

   Code for |
  patient's |
        sex |      Freq.     Percent        Cum.
------------+-----------------------------------
            |        725        7.25        7.25
          F |      6,043       60.43       67.68
          M |      3,227       32.27       99.95
         NS |          1        0.01       99.96
        UNK |          4        0.04      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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