Frequencies for first 10,000 rows of bloodalc variable in nhamcsed1996 dataset : blood | alcohol | concentrati | on | Freq. Percent Cum. ------------+----------------------------------- 0 | 9,778 97.78 97.78 1 | 222 2.22 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016