Frequencies for first 10,000 rows of ctnhead variable in nhamcsed2007 dataset :

  ct scan - |
 other than |
       head |      Freq.     Percent        Cum.
------------+-----------------------------------
         no |      9,283       92.83       92.83
        yes |        717        7.17      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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