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

       DRUG |
DETERMINATI |
         ON |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        164        1.64        1.64
          2 |         30        0.30        1.94
          3 |          9        0.09        2.03
          7 |        110        1.10        3.13
          8 |      9,687       96.87      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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