Frequencies for first 10,000 rows of prov2065 variable in pos1997 dataset :

       srv: |
    alcohol |
and/or drug |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,792       87.92       87.92
          0 |        916        9.16       97.08
          1 |        217        2.17       99.25
          2 |         52        0.52       99.77
          3 |         23        0.23      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 26 Jan 2016