Frequencies for first 10,000 rows of drg4ing3 variable in nhamcsed2005 dataset :

                             ing. #3 |      Freq.     Percent        Cum.
-------------------------------------+-----------------------------------
                            caffeine |          1        0.01        0.01
                isometheptene mucate |          1        0.01        0.02
                           lidocaine |          1        0.01        0.03
                  magnesium antacids |          2        0.02        0.05
                 phenylpropanolamine |          1        0.01        0.06
                          riboflavin |          3        0.03        0.09
                     scopolamine hbr |          1        0.01        0.10
                     sodium chloride |          1        0.01        0.11
                    atropine sulfate |          4        0.04        0.15
                 polymyxin b sulfate |          2        0.02        0.17
                dextromethorphan hbr |          1        0.01        0.18
                    neomycin sulfate |          2        0.02        0.20
                 pheniramine maleate |          1        0.01        0.21
              carbetapentane tannate |          2        0.02        0.23
                orphenadrine citrate |          1        0.01        0.24
                                   . |      9,976       99.76      100.00
-------------------------------------+-----------------------------------
                               Total |     10,000      100.00

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