Frequencies for v_config variable in vehicle dataset :

    VEHICLE |
CONFIGURATI |
         ON |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        422       89.41       89.41
         19 |         19        4.03       93.43
         21 |          2        0.42       93.86
         99 |         29        6.14      100.00
------------+-----------------------------------
      Total |        472      100.00

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