Frequencies for first 10,000 rows of nocharge variable in nhamcsed1992 dataset :

   Expected |
  source of |
 payment-No |
     charge |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,919       99.19       99.19
          1 |         81        0.81      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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