Frequencies for first 10,000 rows of urf_phyper variable in natl2014 dataset :

  Pregnancy |
 Associated |
Hypertensio |
    n 1 Yes |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        707        7.07        7.07
          2 |      9,165       91.65       98.72
          9 |        128        1.28      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 15 Jun 2016