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

  DRUG TEST |
     TYPE-1 |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      6,878       68.78       68.78
          1 |      2,840       28.40       97.18
          2 |         53        0.53       97.71
          3 |         95        0.95       98.66
          7 |          7        0.07       98.73
          8 |         31        0.31       99.04
          9 |         96        0.96      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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