Frequencies for first 10,000 rows of prov6220 variable in pos2005 dataset :

       srv: |
  opthalmic |
    surgery |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,731       87.31       87.31
          0 |      1,249       12.49       99.80
          1 |         17        0.17       99.97
          2 |          2        0.02       99.99
          3 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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