Frequencies for first 10,000 rows of bac variable in nhamcsed2005 dataset :

      blood |
    alcohol |      Freq.     Percent        Cum.
------------+-----------------------------------
         no |      9,735       97.35       97.35
        yes |        265        2.65      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 28 Mar 2016