Frequencies for first 10,000 rows of pregnant variable in namcs2006 dataset :

 if female, is |
       patient |
     pregnant? |      Freq.     Percent        Cum.
---------------+-----------------------------------
           yes |        157        1.57        1.57
            no |      4,690       46.90       48.47
       unknown |        561        5.61       54.08
not applicable |      4,257       42.57       96.65
         blank |        335        3.35      100.00
---------------+-----------------------------------
         Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 28 Mar 2016