Frequencies for first 10,000 rows of f_alcol variable in natl2005 dataset :

Alcohol use |
          U |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |         15        0.15        0.15
          1 |      9,985       99.85      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 22 Dec 2015