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

Underride/O |
    verride |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,920       99.20       99.20
          1 |         22        0.22       99.42
          2 |          3        0.03       99.45
          3 |         13        0.13       99.58
          4 |          5        0.05       99.63
          7 |         15        0.15       99.78
          9 |         22        0.22      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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