Frequencies for first 10,000 rows of rx7v2c3 variable in nhamcsopd2006 dataset :

        for rx7, level 2 of multum drug |
                            category #3 |      Freq.     Percent        Cum.
----------------------------------------+-----------------------------------
CNS: Antiemetic/antivertigo agents: 5HT |          1        0.01        0.01
                 Hormones: sex hormones |          2        0.02        0.03
Miscellaneous agents: genitourinary tra |          1        0.01        0.04
                                      . |      9,996       99.96      100.00
----------------------------------------+-----------------------------------
                                  Total |     10,000      100.00

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