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

  DRUG TEST |
     TYPE-3 |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,872       98.72       98.72
          1 |         61        0.61       99.33
          2 |         14        0.14       99.47
          3 |         17        0.17       99.64
          7 |          2        0.02       99.66
          8 |         32        0.32       99.98
          9 |          2        0.02      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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