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

underride/o |
    verride |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,922       99.22       99.22
          1 |         31        0.31       99.53
          2 |          2        0.02       99.55
          3 |         18        0.18       99.73
          4 |          6        0.06       99.79
          7 |         16        0.16       99.95
          9 |          5        0.05      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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