Frequencies for first 10,000 rows of cthead variable in nhamcsed2014 dataset :

   CT scan- |
       head |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      9,253       92.53       92.53
        Yes |        747        7.47      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 11 Apr 2017