Frequencies for first 10,000 rows of prov1760 variable in pos1995 dataset :

      renal |
   dialysis |
center code |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      9,881       98.81       98.81
          A |        113        1.13       99.94
          B |          5        0.05       99.99
          C |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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