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

  DRUG TEST |
     TYPE-1 |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      7,000       70.00       70.00
          1 |      1,164       11.64       81.64
          2 |         92        0.92       82.56
          3 |        244        2.44       85.00
          7 |        119        1.19       86.19
          8 |         25        0.25       86.44
          9 |      1,356       13.56      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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