Frequencies for first 10,000 rows of sigcolon variable in namcs2010 dataset : sigmoidosco | py/colonosc | opy | Freq. Percent Cum. ------------+----------------------------------- no | 9,915 99.15 99.15 yes | 85 0.85 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016