Frequencies for first 10,000 rows of dr_pres variable in vehicle dataset :

     DRIVER |
   PRESENCE |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      9,857       98.57       98.57
          2 |         62        0.62       99.19
          3 |         81        0.81      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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