Frequencies for first 10,000 rows of mri variable in nhamcsed2005 dataset :

   mri scan |      Freq.     Percent        Cum.
------------+-----------------------------------
         no |      9,936       99.36       99.36
        yes |         64        0.64      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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