Frequencies for first 10,000 rows of injury variable in nhamcsed2009 dataset : is visit | related to | injury or | poisoning? | Freq. Percent Cum. ------------+----------------------------------- 0 | 6,658 66.58 66.58 1 | 3,342 33.42 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016