Frequencies for sp_limit variable in accident dataset :

SPEED LIMIT |      Freq.     Percent        Cum.
------------+-----------------------------------
         20 |          1        0.26        0.26
         25 |         27        7.03        7.29
         30 |          6        1.56        8.85
         35 |        201       52.34       61.20
         40 |         18        4.69       65.89
         45 |         42       10.94       76.82
         50 |         10        2.60       79.43
         55 |          6        1.56       80.99
         65 |         73       19.01      100.00
------------+-----------------------------------
      Total |        384      100.00

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