Frequencies for first 10,000 rows of othblood variable in nhamcsopd2003 dataset : other blood | test | Freq. Percent Cum. ------------+----------------------------------- no | 8,784 87.84 87.84 yes | 1,216 12.16 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016