Frequencies for first 10,000 rows of drugtst3 variable in person dataset :

  DRUG TEST |
     TYPE-3 |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,496       94.96       94.96
          1 |        129        1.29       96.25
          2 |         16        0.16       96.41
          3 |         23        0.23       96.64
          7 |          2        0.02       96.66
          8 |         10        0.10       96.76
          9 |        324        3.24      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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