Frequencies for first 10,000 rows of rf_ghyp variable in natl2013 dataset :

Gestational |
Hypertensio |
      n RFP |
585=f_rf_gh |
     yper R |      Freq.     Percent        Cum.
------------+-----------------------------------
          N |      9,021       90.21       90.21
          U |        167        1.67       91.88
          Y |        812        8.12      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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