Frequencies for first 10,000 rows of drg3ing4 variable in nhamcsed2005 dataset :

                             ing. #4 |      Freq.     Percent        Cum.
-------------------------------------+-----------------------------------
                             menthol |          1        0.01        0.01
                       potassium ion |          4        0.04        0.05
                      sodium sulfate |          1        0.01        0.06
                            thiamine |          6        0.06        0.12
                           vitamin c |          1        0.01        0.13
                 hyoscyamine sulfate |         10        0.10        0.23
                 diphenhydramine hcl |          1        0.01        0.24
                   ephedrine tannate |          1        0.01        0.25
                                   . |      9,975       99.75      100.00
-------------------------------------+-----------------------------------
                               Total |     10,000      100.00

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