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

  DRUG TEST |
     TYPE-1 |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      6,493       64.93       64.93
          1 |      1,875       18.75       83.68
          2 |         96        0.96       84.64
          3 |        238        2.38       87.02
          7 |         66        0.66       87.68
          8 |         46        0.46       88.14
          9 |      1,186       11.86      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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