Frequencies for first 10,000 rows of othblood variable in nhamcsopd2001 dataset : other blood | test | Freq. Percent Cum. ------------+----------------------------------- 0 | 8,427 84.27 84.27 1 | 1,573 15.73 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016