Frequencies for first 10,000 rows of mri variable in nhamcsed2012 dataset :

        MRI |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      9,942       99.42       99.42
        Yes |         58        0.58      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 7 Nov 2016