Frequencies for first 10,000 rows of cthead variable in nhamcsed2015 dataset :

   CT scan- |
       head |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      9,254       92.54       92.54
        Yes |        746        7.46      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 20 Nov 2017