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

Gestational |
Hypertensio |
      n RFP |
585=f_rf_gh |
     yper R |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      6,163       61.63       61.63
          N |      3,700       37.00       98.63
          U |          1        0.01       98.64
          Y |        136        1.36      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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