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

  DRUG TEST |
     TYPE-1 |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      6,816       68.16       68.16
          1 |      2,009       20.09       88.25
          2 |        103        1.03       89.28
          3 |        197        1.97       91.25
          7 |        100        1.00       92.25
          8 |         32        0.32       92.57
          9 |        743        7.43      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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