Frequencies for first 10,000 rows of drugtst2 variable in person dataset :

  DRUG TEST |
     TYPE-2 |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,808       98.08       98.08
          1 |         90        0.90       98.98
          2 |         51        0.51       99.49
          3 |         11        0.11       99.60
          7 |          2        0.02       99.62
          8 |          5        0.05       99.67
          9 |         33        0.33      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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