Frequencies for first 10,000 rows of hivstdtr variable in nhamcsopd1999 dataset : hiv/std | transmissio | n | couns/educ | Freq. Percent Cum. ------------+----------------------------------- 0 | 9,810 98.10 98.10 1 | 190 1.90 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016