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

  DRUG TEST |
     TYPE-3 |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,689       96.89       96.89
          1 |         96        0.96       97.85
          2 |         13        0.13       97.98
          3 |         17        0.17       98.15
          7 |          3        0.03       98.18
          8 |          3        0.03       98.21
          9 |        179        1.79      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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