Frequencies for first 10,000 rows of drug4cl3 variable in nhamcsopd2005 dataset :

          ndc code #3 for medication #4 |      Freq.     Percent        Cum.
----------------------------------------+-----------------------------------
                         ace inhibitors |          1        0.01        0.01
                        anticonvulsants |          2        0.02        0.03
                           antipyretics |         54        0.54        0.57
                         antihistamines |          5        0.05        0.62
                          cold remedies |          5        0.05        0.67
                          surgical aids |          3        0.03        0.70
                                      . |      9,930       99.30      100.00
----------------------------------------+-----------------------------------
                                  Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 28 Mar 2016