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

  drug test |
  -type (3) |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,580       95.80       95.80
          1 |        408        4.08       99.88
          2 |          4        0.04       99.92
          6 |          2        0.02       99.94
          7 |          1        0.01       99.95
          8 |          5        0.05      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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