Frequencies for first 10,000 rows of drug4cl3 variable in nhamcsopd2002 dataset :

 drug class |
     #3 for |
 medication |
         #4 |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      9,956       99.56       99.56
       1374 |          4        0.04       99.60
       1728 |         34        0.34       99.94
       1940 |          1        0.01       99.95
       1941 |          2        0.02       99.97
       1944 |          2        0.02       99.99
       1945 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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