Frequencies for first 10,000 rows of bac variable in nhamcsed2012 dataset :

      Blood |
    alcohol |
concentrati |
         on |      Freq.     Percent        Cum.
------------+-----------------------------------
         No |      9,707       97.07       97.07
        Yes |        293        2.93      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 7 Nov 2016