Frequencies for first 10,000 rows of harm_ev variable in vehicle dataset :

      First |
    Harmful |
      Event |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        917        9.17        9.17
          2 |          6        0.06        9.23
          3 |          7        0.07        9.30
          4 |          2        0.02        9.32
          5 |         61        0.61        9.93
          6 |          1        0.01        9.94
          7 |          7        0.07       10.01
          8 |      1,168       11.68       21.69
          9 |        129        1.29       22.98
         10 |         72        0.72       23.70
         11 |         16        0.16       23.86
         12 |      5,357       53.57       77.43
         13 |         48        0.48       77.91
         14 |        171        1.71       79.62
         16 |         25        0.25       79.87
         17 |        120        1.20       81.07
         18 |          9        0.09       81.16
         19 |        129        1.29       82.45
         20 |        345        3.45       85.90
         21 |         55        0.55       86.45
         22 |        315        3.15       89.60
         23 |         96        0.96       90.56
         24 |        192        1.92       92.48
         25 |         24        0.24       92.72
         26 |         32        0.32       93.04
         27 |        308        3.08       96.12
         28 |        213        2.13       98.25
         29 |         50        0.50       98.75
         31 |        109        1.09       99.84
         99 |         16        0.16      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 22 Apr 2016