Frequencies for drugtst1 variable in person dataset :

  DRUG TEST |
     TYPE-1 |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        496       60.78       60.78
          1 |        320       39.22      100.00
------------+-----------------------------------
      Total |        816      100.00

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