Frequencies for first 10,000 rows of refin variable in namcs2013 dataset :

   Do you see any |
patients referred |
        to you by |
providers outside |
of your office or |
                g |      Freq.     Percent        Cum.
------------------+-----------------------------------
            Blank |         20        0.20        0.20
          Unknown |          1        0.01        0.21
              Yes |      8,530       85.30       85.51
               No |      1,449       14.49      100.00
------------------+-----------------------------------
            Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 27 Mar 2017