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

      SPEC: |
OPTHAMOLOGY |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      9,632       96.32       96.32
          N |        156        1.56       97.88
          Y |        212        2.12      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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