Frequencies for first 10,000 rows of prov2030 variable in pos1993 dataset :

       self |
   dialysis |
certificati |
         on |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      9,899       98.99       98.99
          A |         82        0.82       99.81
          B |         15        0.15       99.96
          E |          4        0.04      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 26 Jan 2016