Frequencies for first 10,000 rows of dr_sf4 variable in vehicle dataset :

     driver |
    related |
 factors (4 |
   choices) |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,568       95.68       95.68
         21 |          1        0.01       95.69
         34 |          1        0.01       95.70
         36 |          1        0.01       95.71
         39 |          2        0.02       95.73
         48 |          1        0.01       95.74
         52 |          1        0.01       95.75
         53 |          1        0.01       95.76
         87 |          1        0.01       95.77
         91 |          2        0.02       95.79
         99 |        421        4.21      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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