Frequencies for first 10,000 rows of drg7ing4 variable in nhamcsed2005 dataset :

                             ing. #4 |      Freq.     Percent        Cum.
-------------------------------------+-----------------------------------
                          riboflavin |          1        0.01        0.01
                            thiamine |          1        0.01        0.02
                        vitamin b-12 |          1        0.01        0.03
                                   . |      9,997       99.97      100.00
-------------------------------------+-----------------------------------
                               Total |     10,000      100.00

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