Frequencies for first 10,000 rows of prov6170 variable in pos2006 dataset :

       srv: |
chemotherap |
  y service |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,710       87.10       87.10
          0 |      1,246       12.46       99.56
          1 |         40        0.40       99.96
          2 |          1        0.01       99.97
          3 |          3        0.03      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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