Frequencies for first 10,000 rows of a_drdro variable in veh_aux dataset :

     Drowsy |
     Driver |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        294        2.94        2.94
          2 |      9,706       97.06      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 18 Apr 2016