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

UNDERRIDE/O |
    VERRIDE |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,917       99.17       99.17
          1 |         29        0.29       99.46
          2 |          7        0.07       99.53
          3 |         12        0.12       99.65
          4 |          6        0.06       99.71
          6 |          2        0.02       99.73
          7 |         25        0.25       99.98
          8 |          1        0.01       99.99
          9 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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