Frequencies for first 10,000 rows of prov2285 variable in pos2006 dataset :

       srv: |
cardio-thor |
       acic |
    surgery |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,710       87.10       87.10
          0 |      1,032       10.32       97.42
          1 |        204        2.04       99.46
          2 |         47        0.47       99.93
          3 |          7        0.07      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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