Frequencies for first 10,000 rows of drugtst2 variable in person dataset :

  drug test |
  -type (2) |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,332       93.32       93.32
          1 |        637        6.37       99.69
          2 |         18        0.18       99.87
          3 |          3        0.03       99.90
          7 |          4        0.04       99.94
          8 |          6        0.06      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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