Frequencies for first 10,000 rows of pregtest variable in nhamcsed2012 dataset :

  Pregnancy |
       test |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      9,422       94.22       94.22
        Yes |        578        5.78      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 7 Nov 2016