Frequencies for first 10,000 rows of ehxfu variable in namcs2009 dataset :

       if yes, |
       include |
       medical |
history/follow |
    -up notes? |      Freq.     Percent        Cum.
---------------+-----------------------------------
         blank |        116        1.16        1.16
       unknown |        189        1.89        3.05
not applicable |      4,901       49.01       52.06
           yes |      4,685       46.85       98.91
            no |        109        1.09      100.00
---------------+-----------------------------------
         Total |     10,000      100.00

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