Frequencies for sp_limit variable in accident dataset :

Speed Limit |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |          1        0.21        0.21
         20 |          3        0.62        0.82
         25 |         64       13.17       13.99
         30 |         19        3.91       17.90
         35 |        164       33.74       51.65
         40 |         81       16.67       68.31
         45 |         67       13.79       82.10
         50 |         33        6.79       88.89
         55 |         54       11.11      100.00
------------+-----------------------------------
      Total |        486      100.00

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