Frequencies for first 10,000 rows of refunins variable in namcs2003 dataset :

 difficulty |
  referring |
  uninsured |
    pat for |
       cons |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        262        2.62        2.62
          1 |      1,399       13.99       16.61
          2 |      1,341       13.41       30.02
          3 |      1,032       10.32       40.34
          4 |      4,364       43.64       83.98
          5 |      1,602       16.02      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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