Frequencies for first 10,000 rows of prov2065 variable in pos1991 dataset :

       srv: |
    alcohol |
and/or drug |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,770       87.70       87.70
          0 |        944        9.44       97.14
          1 |        199        1.99       99.13
          2 |         58        0.58       99.71
          3 |         29        0.29      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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