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

 difficulty |
         in |
  referring |
   medicare |
   patients |
        for |
  specialty |
consultatio |
          n |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |         67        0.67        0.67
          1 |        168        1.68        2.35
          2 |        675        6.75        9.10
          3 |      1,109       11.09       20.19
          4 |      5,448       54.48       74.67
          5 |        684        6.84       81.51
          6 |      1,849       18.49      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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