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

  DRUG TEST |
     TYPE-3 |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,918       99.18       99.18
          1 |         39        0.39       99.57
          2 |         12        0.12       99.69
          3 |         12        0.12       99.81
          7 |          1        0.01       99.82
          8 |         17        0.17       99.99
          9 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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