Frequencies for first 10,000 rows of drg5ing5 variable in nhamcsopd2004 dataset : ingredient code #5 for medication | #5 | Freq. Percent Cum. ------------------------------------+----------------------------------- sodium ion | 2 0.02 0.02 vitamin a | 5 0.05 0.07 vitamin c | 1 0.01 0.08 . | 9,992 99.92 100.00 ------------------------------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016