Frequencies for first 10,000 rows of retinal variable in namcs2012 dataset :

    Retinal |
       exam |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      9,738       97.38       97.38
        Yes |        262        2.62      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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