Frequencies for first 10,000 rows of rx2v1c3 variable in nhamcsopd2006 dataset :

   for rx2, level 1 of multum |
             drug category #3 |      Freq.     Percent        Cum.
------------------------------+-----------------------------------
Central nervous system agents |         26        0.26        0.26
                     Hormones |         11        0.11        0.37
         Miscellaneous agents |          9        0.09        0.46
           Respiratory agents |          1        0.01        0.47
                            . |      9,953       99.53      100.00
------------------------------+-----------------------------------
                        Total |     10,000      100.00

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