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

Underride/O |
    verride |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,926       99.26       99.26
          1 |         27        0.27       99.53
          2 |          4        0.04       99.57
          3 |         12        0.12       99.69
          4 |          4        0.04       99.73
          5 |          1        0.01       99.74
          7 |         18        0.18       99.92
          9 |          8        0.08      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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