Frequencies for trav_sp variable in vehicle dataset :

     TRAVEL |
      SPEED |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |          7        1.12        1.12
         10 |          1        0.16        1.28
         25 |          1        0.16        1.44
         30 |          1        0.16        1.60
         35 |          3        0.48        2.08
         40 |          3        0.48        2.56
         45 |          1        0.16        2.72
         47 |          1        0.16        2.88
         50 |          3        0.48        3.35
         55 |          1        0.16        3.51
         57 |          1        0.16        3.67
         65 |          1        0.16        3.83
         80 |          1        0.16        3.99
         88 |          1        0.16        4.15
         97 |          2        0.32        4.47
         99 |        598       95.53      100.00
------------+-----------------------------------
      Total |        626      100.00

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