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

  DRUG TEST |
     TYPE-3 |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,467       94.67       94.67
          1 |         92        0.92       95.59
          2 |         11        0.11       95.70
          3 |          5        0.05       95.75
          7 |          1        0.01       95.76
          9 |        424        4.24      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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