Frequencies for first 10,000 rows of mri variable in nhamcsed2015 dataset :

        MRI |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      9,923       99.23       99.23
        Yes |         77        0.77      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 20 Nov 2017