Frequencies for first 10,000 rows of payself variable in nhamcsed2011 dataset :

   Expected |
  source of |
   payment: |
   Self-pay |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      8,633       86.33       86.33
        Yes |      1,367       13.67      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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