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

  drug test |
  -type (3) |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,665       96.65       96.65
          1 |        332        3.32       99.97
          2 |          1        0.01       99.98
          3 |          1        0.01       99.99
          8 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 22 Oct 2016