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

 difficulty |
  referring |
 priv insur |
    pat for |
       cons |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        269        2.69        2.69
          1 |        301        3.01        5.70
          2 |        860        8.60       14.30
          3 |      1,799       17.99       32.29
          4 |      5,917       59.17       91.46
          5 |        854        8.54      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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