Frequencies for first 10,000 rows of sex variable in demo2007q4 dataset :

   Code for |
  patient's |
        sex |      Freq.     Percent        Cum.
------------+-----------------------------------
            |        750        7.50        7.50
          F |      5,657       56.57       64.07
          M |      3,571       35.71       99.78
         NS |         12        0.12       99.90
        UNK |         10        0.10      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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