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

  DRUG TEST |
     TYPE-1 |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      7,219       72.19       72.19
          1 |      1,227       12.27       84.46
          2 |        197        1.97       86.43
          3 |         63        0.63       87.06
          7 |        122        1.22       88.28
          8 |         29        0.29       88.57
          9 |      1,143       11.43      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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