Frequencies for drugres3 variable in person dataset :

  DRUG TEST |
  RESULTS-3 |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        815       99.88       99.88
        117 |          1        0.12      100.00
------------+-----------------------------------
      Total |        816      100.00

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