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

SPEED LIMIT |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |         39        0.39        0.39
         10 |          5        0.05        0.44
         15 |         20        0.20        0.64
         20 |         26        0.26        0.90
         25 |        543        5.43        6.33
         30 |        524        5.24       11.57
         35 |      1,216       12.16       23.73
         40 |        923        9.23       32.96
         45 |      1,441       14.41       47.37
         50 |        504        5.04       52.41
         55 |      3,850       38.50       90.91
         60 |          3        0.03       90.94
         65 |        650        6.50       97.44
         75 |          1        0.01       97.45
         99 |        255        2.55      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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