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

  CT scan - |
   site not |
  specified |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      9,920       99.20       99.20
        Yes |         80        0.80      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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