Frequencies for first 10,000 rows of bac variable in nhamcsed2001 dataset : blood | alcohol | Freq. Percent Cum. ------------+----------------------------------- 0 | 9,818 98.18 98.18 1 | 182 1.82 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016