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

Speed Limit |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |         23        0.23        0.23
         15 |         33        0.33        0.56
         20 |         20        0.20        0.76
         25 |        755        7.55        8.31
         30 |        599        5.99       14.30
         35 |      1,426       14.26       28.56
         40 |        834        8.34       36.90
         45 |      1,142       11.42       48.32
         50 |        427        4.27       52.59
         55 |      4,390       43.90       96.49
         99 |        351        3.51      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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