Frequencies for first 10,000 rows of refmdcar variable in namcs2004 dataset :

 difficulty |
  referring |
   medicare |
    pat for |
    consult |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        472        4.72        4.72
          1 |        122        1.22        5.94
          2 |        604        6.04       11.98
          3 |      1,307       13.07       25.05
          4 |      5,903       59.03       84.08
          5 |      1,592       15.92      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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