Frequencies for first 10,000 rows of catmri variable in nhamcsopd1997 dataset :

catscan/mri |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,803       98.03       98.03
          1 |        197        1.97      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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