Frequencies for first 10,000 rows of prov2065 variable in pos1995 dataset :

       srv: |
    alcohol |
and/or drug |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,933       89.33       89.33
          0 |        812        8.12       97.45
          1 |        181        1.81       99.26
          2 |         49        0.49       99.75
          3 |         25        0.25      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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