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

  DRUG TEST |
     TYPE-2 |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,787       97.87       97.87
          1 |         88        0.88       98.75
          2 |         56        0.56       99.31
          3 |          7        0.07       99.38
          7 |          3        0.03       99.41
          8 |          1        0.01       99.42
          9 |         58        0.58      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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