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

  Drug Test |
  -Type (3) |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,730       97.30       97.30
          1 |        253        2.53       99.83
          2 |         11        0.11       99.94
          6 |          1        0.01       99.95
          7 |          1        0.01       99.96
          8 |          4        0.04      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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