Frequencies for first 10,000 rows of mri variable in nhamcsopd2005 dataset :

 mri/ct/pet |      Freq.     Percent        Cum.
------------+-----------------------------------
         no |      9,513       95.13       95.13
        yes |        487        4.87      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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