Frequencies for first 10,000 rows of cervcx variable in nhamcsed2003 dataset : cervical/ur | ethral | culture | Freq. Percent Cum. ------------+----------------------------------- no | 9,932 99.32 99.32 yes | 68 0.68 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016