Frequencies for first 10,000 rows of prov1760 variable in pos1992 dataset :

      renal |
   dialysis |
center code |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      9,889       98.89       98.89
          A |        109        1.09       99.98
          B |          1        0.01       99.99
          C |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 17 May 2017