Frequencies for first 10,000 rows of sigcolon variable in nhamcsopd2007 dataset : sigmoidosco | py/colonosc | opy | Freq. Percent Cum. ------------+----------------------------------- no | 9,881 98.81 98.81 yes | 119 1.19 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016