Frequencies for first 10,000 rows of drugtst1 variable in person dataset :

  drug test |
  -type (1) |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      5,906       59.06       59.06
          1 |      3,559       35.59       94.65
          2 |         28        0.28       94.93
          3 |          4        0.04       94.97
          6 |        447        4.47       99.44
          7 |          7        0.07       99.51
          8 |         29        0.29       99.80
          9 |         20        0.20      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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