Frequencies for first 10,000 rows of prov2025 variable in pos1993 dataset :

       self |
   dialysis |
       code |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      9,949       99.49       99.49
          A |         50        0.50       99.99
          B |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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