Frequencies for first 10,000 rows of rf_ghyp variable in natlterr2011 dataset :

Gestational |
Hypertensio |
      n RFP |
585=f_rf_gh |
     yper R |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      2,536       25.36       25.36
          N |      6,232       62.32       87.68
          U |      1,074       10.74       98.42
          Y |        158        1.58      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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