Frequencies for first 10,000 rows of drg4ing5 variable in nhamcsed1999 dataset : ingredient | code #5 for | drug #4 | Freq. Percent Cum. ------------+----------------------------------- | 9,999 99.99 99.99 56345 | 1 0.01 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016