Frequencies for first 10,000 rows of bac variable in nhamcsed2007 dataset :

      blood |
    alcohol |      Freq.     Percent        Cum.
------------+-----------------------------------
         no |      9,651       96.51       96.51
        yes |        349        3.49      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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