Frequencies for first 10,000 rows of bloodalc variable in nhamcsed1995 dataset : blood | alcohol | concentrati | on | Freq. Percent Cum. ------------+----------------------------------- 0 | 9,837 98.37 98.37 1 | 163 1.63 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016