Frequencies for first 10,000 rows of ctnhead variable in nhamcsed2008 dataset :

  ct scan - |
 other than |
       head |      Freq.     Percent        Cum.
------------+-----------------------------------
         no |      9,219       92.19       92.19
        yes |        781        7.81      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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