Frequencies for first 10,000 rows of payself variable in nhamcsed2010 dataset :

   Expected |
  source of |
   payment: |
   Self pay |      Freq.     Percent        Cum.
------------+-----------------------------------
         no |      7,912       79.12       79.12
        yes |      2,088       20.88      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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