Frequencies for first 10,000 rows of nnochrge variable in namcs2007 dataset :

       for new |
     patients, |
    accepts no |
        charge |      Freq.     Percent        Cum.
---------------+-----------------------------------
         blank |         82        0.82        0.82
       unknown |        908        9.08        9.90
not applicable |        659        6.59       16.49
           yes |      3,777       37.77       54.26
            no |      4,574       45.74      100.00
---------------+-----------------------------------
         Total |     10,000      100.00

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