Frequencies for first 10,000 rows of prov6220 variable in pos2010 dataset :

       SRV: |
  OPTHALMIC |
    SURGERY |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,626       86.26       86.26
          0 |      1,203       12.03       98.29
          1 |        128        1.28       99.57
          2 |         23        0.23       99.80
          3 |         20        0.20      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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