Frequencies for first 10,000 rows of rf_phype variable in natl2017 dataset :

Pre-pregnan |
         cy |
Hypertensio |
    n Y Yes |      Freq.     Percent        Cum.
------------+-----------------------------------
          N |      9,569       95.69       95.69
          U |         90        0.90       96.59
          Y |        341        3.41      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 19 Sep 2018