Frequencies for first 10,000 rows of injury variable in nhamcsopd1999 dataset : is this | visit | related to | injury or | poisoning? | Freq. Percent Cum. ------------+----------------------------------- 0 | 8,998 89.98 89.98 1 | 1,002 10.02 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016