Frequencies for first 10,000 rows of rf_gest variable in natlterr2007 dataset :

Gestational |
   Diabetes |
        RFP |
583=f_rf_gd |
      iab R |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      6,163       61.63       61.63
          N |      3,758       37.58       99.21
          U |          1        0.01       99.22
          Y |         78        0.78      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 22 Dec 2015