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

  drug test |
  -type (3) |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,633       96.33       96.33
          1 |        345        3.45       99.78
          2 |         14        0.14       99.92
          7 |          4        0.04       99.96
          8 |          4        0.04      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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