Frequencies for first 10,000 rows of paynochg variable in nhamcsed2007 dataset :

  no charge |      Freq.     Percent        Cum.
------------+-----------------------------------
         no |      9,839       98.39       98.39
        yes |        161        1.61      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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