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 |         33        0.33       99.50
          2 |          6        0.06       99.56
          3 |         14        0.14       99.70
          4 |          6        0.06       99.76
          6 |          1        0.01       99.77
          7 |         21        0.21       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