Frequencies for first 10,000 rows of rf_ghyp variable in natlterr2010 dataset :

Gestational |
Hypertensio |
      n RFP |
585=f_rf_gh |
     yper R |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      4,656       46.56       46.56
          N |      4,429       44.29       90.85
          U |        767        7.67       98.52
          Y |        148        1.48      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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