Frequencies for first 10,000 rows of rx7v1c2 variable in nhamcsed2006 dataset :

   for rx7, level 1 of multum |
             drug category #2 |      Freq.     Percent        Cum.
------------------------------+-----------------------------------
              anti-infectives |          5        0.05        0.05
        cardiovascular agents |          4        0.04        0.09
central nervous system agents |          7        0.07        0.16
         miscellaneous agents |          3        0.03        0.19
         nutritional products |          1        0.01        0.20
           respiratory agents |          3        0.03        0.23
               topical agents |          1        0.01        0.24
     psychotherapeutic agents |          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