Frequencies for first 10,000 rows of sp_limit variable in accident dataset :

SPEED LIMIT |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |         25        0.25        0.25
         10 |          5        0.05        0.30
         15 |         18        0.18        0.48
         20 |         22        0.22        0.70
         25 |        517        5.17        5.87
         30 |        533        5.33       11.20
         35 |      1,192       11.92       23.12
         40 |        890        8.90       32.02
         45 |      1,542       15.42       47.44
         50 |        494        4.94       52.38
         55 |      3,077       30.77       83.15
         60 |         30        0.30       83.45
         65 |        934        9.34       92.79
         70 |        383        3.83       96.62
         75 |        100        1.00       97.62
         99 |        238        2.38      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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