Frequencies for first 10,000 rows of drg5ing4 variable in nhamcsed2005 dataset :

                             ing. #4 |      Freq.     Percent        Cum.
-------------------------------------+-----------------------------------
                          phenacetin |          1        0.01        0.01
                       potassium ion |          1        0.01        0.02
                            thiamine |          1        0.01        0.03
                           vitamin a |          1        0.01        0.04
                 hyoscyamine sulfate |          1        0.01        0.05
                         lipoic acid |          1        0.01        0.06
                                   . |      9,994       99.94      100.00
-------------------------------------+-----------------------------------
                               Total |     10,000      100.00

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