Frequencies for first 10,000 rows of drug_det variable in person dataset :

       DRUG |
DETERMAINAT |
        ION |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         71        0.71        0.71
          2 |          5        0.05        0.76
          3 |         16        0.16        0.92
          7 |         63        0.63        1.55
          8 |      9,845       98.45      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 18 Apr 2016