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

       DRUG |
DETERMAINAT |
        ION |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         58        0.58        0.58
          2 |          8        0.08        0.66
          3 |          4        0.04        0.70
          7 |         41        0.41        1.11
          8 |      9,889       98.89      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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