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

underride/o |
    verride |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,914       99.14       99.14
          1 |         42        0.42       99.56
          2 |          3        0.03       99.59
          3 |         22        0.22       99.81
          4 |          2        0.02       99.83
          6 |          1        0.01       99.84
          7 |          8        0.08       99.92
          8 |          1        0.01       99.93
          9 |          7        0.07      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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