Frequencies for first 10,000 rows of prov2290 variable in pos2001 dataset :

      spec: |
opthamology |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      9,267       92.67       92.67
          N |        375        3.75       96.42
          Y |        358        3.58      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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