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

     driver |
   presence |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |         51        0.51        0.51
          1 |      9,949       99.49      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 22 Oct 2016