Frequencies for first 10,000 rows of payself variable in nhamcsed2009 dataset :

   expected |
  source of |
   payment: |
   self pay |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      8,468       84.68       84.68
          1 |      1,532       15.32      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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