Frequencies for first 10,000 rows of retinal variable in namcs2010 dataset :

    retinal |
       exam |      Freq.     Percent        Cum.
------------+-----------------------------------
         no |      9,761       97.61       97.61
        yes |        239        2.39      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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