Frequencies for first 10,000 rows of pregnant variable in namcs2015 dataset :

 Is patient |
  pregnant? |      Freq.     Percent        Cum.
------------+-----------------------------------
         -9 |      2,544       25.44       25.44
         -7 |      4,377       43.77       69.21
          1 |        318        3.18       72.39
          2 |      2,761       27.61      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 25 Oct 2017