Frequencies for first 10,000 rows of ehxfu variable in namcs2008 dataset :

       if yes, |
       include |
       medical |
history/follow |
    -up notes? |      Freq.     Percent        Cum.
---------------+-----------------------------------
         blank |        239        2.39        2.39
       unknown |        214        2.14        4.53
not applicable |      5,212       52.12       56.65
           yes |      4,076       40.76       97.41
            no |        259        2.59      100.00
---------------+-----------------------------------
         Total |     10,000      100.00

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