Frequencies for first 10,000 rows of drg3ing5 variable in nhamcsopd1995 dataset : ingredient | code #5 for | medication | #3 | Freq. Percent Cum. ------------+----------------------------------- | 9,991 99.91 99.91 55755 | 1 0.01 99.92 56185 | 6 0.06 99.98 56193 | 2 0.02 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016