Frequencies for mcarr_id variable in vehicle dataset :

      MOTOR |
 CARRIER ID |      Freq.     Percent        Cum.
------------+-----------------------------------
00000000000 |        422       89.41       89.41
99999999999 |         50       10.59      100.00
------------+-----------------------------------
      Total |        472      100.00

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