Frequencies for first 10,000 rows of brstslfx variable in nhamcsopd1998 dataset : breast | self-exam | couns/educ | Freq. Percent Cum. ------------+----------------------------------- 0 | 9,772 97.72 97.72 1 | 228 2.28 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016