Frequencies for first 10,000 rows of sigcolon variable in namcs2009 dataset :

sigmoidosco |
py/colonosc |
        opy |      Freq.     Percent        Cum.
------------+-----------------------------------
         no |      9,866       98.66       98.66
        yes |        134        1.34      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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