Frequencies for first 10,000 rows of sex variable in demo2010q4 dataset :

   Code for |
  patient's |
        sex |      Freq.     Percent        Cum.
------------+-----------------------------------
            |        590        5.90        5.90
          F |      5,709       57.09       62.99
          M |      3,699       36.99       99.98
         NS |          1        0.01       99.99
        UNK |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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