Frequencies for first 10,000 rows of unkpay variable in nhamcsed1993 dataset :

   expected |
  source of |
payment-unk |
       nown |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,654       96.54       96.54
          1 |        346        3.46      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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