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

  DRUG TEST |
     TYPE-1 |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      6,680       66.80       66.80
          1 |      1,367       13.67       80.47
          2 |        152        1.52       81.99
          3 |        234        2.34       84.33
          7 |         62        0.62       84.95
          8 |         58        0.58       85.53
          9 |      1,447       14.47      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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