Frequencies for first 10,000 rows of herpes variable in natl2001 dataset : Genital | herpes | Freq. Percent Cum. ------------+----------------------------------- 1 | 75 0.75 0.75 2 | 9,921 99.21 99.96 8 | 3 0.03 99.99 9 | 1 0.01 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 22 Dec 2015