Frequencies for first 10,000 rows of rx4cat4 variable in nhamcsed2006 dataset :

     for rx4, multum drug category #4 - |
                               detailed |      Freq.     Percent        Cum.
----------------------------------------+-----------------------------------
cns: anti-parkinson agents: anticholine |         15        0.15        0.15
                                      . |      9,985       99.85      100.00
----------------------------------------+-----------------------------------
                                  Total |     10,000      100.00

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