Frequencies for first 10,000 rows of urf_phyper variable in natl2015 dataset :

  Pregnancy |
 Associated |
Hypertensio |
    n 1 Yes |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        814        8.14        8.14
          2 |      9,078       90.78       98.92
          9 |        108        1.08      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 20 Oct 2016