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

  DRUG TEST |
     TYPE-1 |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      6,585       65.85       65.85
          1 |      3,092       30.92       96.77
          2 |         85        0.85       97.62
          3 |         73        0.73       98.35
          7 |         16        0.16       98.51
          8 |         36        0.36       98.87
          9 |        113        1.13      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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