Frequencies for first 10,000 rows of rx2v1c3 variable in nhamcsed2006 dataset :

   for rx2, level 1 of multum |
             drug category #3 |      Freq.     Percent        Cum.
------------------------------+-----------------------------------
central nervous system agents |         76        0.76        0.76
         miscellaneous agents |          3        0.03        0.79
           respiratory agents |         16        0.16        0.95
                            . |      9,905       99.05      100.00
------------------------------+-----------------------------------
                        Total |     10,000      100.00

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