Frequencies for first 10,000 rows of cervcx variable in nhamcsed2004 dataset : cervical/ur | ethral | culture | Freq. Percent Cum. ------------+----------------------------------- no | 9,923 99.23 99.23 yes | 77 0.77 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016