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

    TRAFFIC |
   CONTROLS |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      6,728       67.28       67.28
          1 |         14        0.14       67.42
          2 |         86        0.86       68.28
          3 |        770        7.70       75.98
          4 |         15        0.15       76.13
          5 |          9        0.09       76.22
          6 |          9        0.09       76.31
          7 |          4        0.04       76.35
          8 |          6        0.06       76.41
          9 |          2        0.02       76.43
         20 |        853        8.53       84.96
         21 |         13        0.13       85.09
         28 |        181        1.81       86.90
         29 |          3        0.03       86.93
         30 |          3        0.03       86.96
         31 |          3        0.03       86.99
         40 |      1,173       11.73       98.72
         50 |         20        0.20       98.92
         60 |         30        0.30       99.22
         61 |         14        0.14       99.36
         62 |          6        0.06       99.42
         64 |          1        0.01       99.43
         70 |         21        0.21       99.64
         71 |          8        0.08       99.72
         72 |          7        0.07       99.79
         78 |          1        0.01       99.80
         98 |          3        0.03       99.83
         99 |         17        0.17      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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