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

 difficulty |
  referring |
 priv insur |
    pat for |
       cons |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        164        1.64        1.64
          1 |        134        1.34        2.98
          2 |      1,041       10.41       13.39
          3 |      1,335       13.35       26.74
          4 |      6,359       63.59       90.33
          5 |        967        9.67      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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