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

SPEED LIMIT |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |         16        0.16        0.16
          5 |          3        0.03        0.19
         10 |          5        0.05        0.24
         15 |         17        0.17        0.41
         20 |         14        0.14        0.55
         25 |        566        5.66        6.21
         30 |        420        4.20       10.41
         35 |      1,073       10.73       21.14
         40 |        929        9.29       30.43
         45 |      1,658       16.58       47.01
         50 |        460        4.60       51.61
         55 |      2,343       23.43       75.04
         60 |        184        1.84       76.88
         65 |      1,276       12.76       89.64
         70 |        605        6.05       95.69
         75 |        183        1.83       97.52
         90 |          1        0.01       97.53
         99 |        247        2.47      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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