Frequencies for first 10,000 rows of rx7v2c3 variable in nhamcsed2006 dataset :

        for rx7, level 2 of multum drug |
                            category #3 |      Freq.     Percent        Cum.
----------------------------------------+-----------------------------------
cns: antiemetic/antivertigo agents: 5ht |          1        0.01        0.01
   miscellaneous agents: antipsoriatics |          1        0.01        0.02
                                      . |      9,998       99.98      100.00
----------------------------------------+-----------------------------------
                                  Total |     10,000      100.00

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