Frequencies for first 10,000 rows of chlamyd variable in namcs2010 dataset : chlamydia | test | Freq. Percent Cum. ------------+----------------------------------- no | 9,941 99.41 99.41 yes | 59 0.59 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016