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

  DRUG TEST |
     TYPE-3 |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,748       97.48       97.48
          1 |        145        1.45       98.93
          2 |         11        0.11       99.04
          3 |         12        0.12       99.16
          8 |          2        0.02       99.18
          9 |         82        0.82      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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