Frequencies for first 10,000 rows of prov2030 variable in pos1991 dataset :

       self |
   dialysis |
certificati |
         on |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      9,892       98.92       98.92
          A |         80        0.80       99.72
          B |         23        0.23       99.95
          E |          5        0.05      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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