Frequencies for first 10,000 rows of visual variable in nhamcsopd1998 dataset :

     visual |
acuity exam |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,640       96.40       96.40
          1 |        360        3.60      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 28 Mar 2016