Frequencies for first 10,000 rows of refpriv variable in namcs2005 dataset :

 difficulty |
         in |
  referring |
    private |
  insurance |
   patients |
        for |
  specialty |
consultatio |
          n |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |         37        0.37        0.37
          1 |        287        2.87        3.24
          2 |        963        9.63       12.87
          3 |      1,765       17.65       30.52
          4 |      6,181       61.81       92.33
          5 |        551        5.51       97.84
          6 |        216        2.16      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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