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

Pre-pregnan |
         cy |
Hypertensio |
    n Y Yes |      Freq.     Percent        Cum.
------------+-----------------------------------
          N |      9,625       96.25       96.25
          U |        108        1.08       97.33
          Y |        267        2.67      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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