Frequencies for first 10,000 rows of injprev variable in nhamcsopd1998 dataset : injury | prevention | couns/educ | Freq. Percent Cum. ------------+----------------------------------- 0 | 9,647 96.47 96.47 1 | 353 3.53 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016