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

  DRUG TEST |
     TYPE-1 |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      6,802       68.02       68.02
          1 |      1,136       11.36       79.38
          2 |        192        1.92       81.30
          3 |        201        2.01       83.31
          7 |        126        1.26       84.57
          8 |         16        0.16       84.73
          9 |      1,527       15.27      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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