Frequencies for first 10,000 rows of ctab variable in nhamcsed2013 dataset :

  CT scan - |
abdomen/pel |
        vis |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      9,514       95.14       95.14
        Yes |        486        4.86      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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