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

UNDERRIDE/O |
    VERRIDE |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,871       98.71       98.71
          1 |         35        0.35       99.06
          2 |          3        0.03       99.09
          3 |         12        0.12       99.21
          4 |         14        0.14       99.35
          5 |          2        0.02       99.37
          6 |          1        0.01       99.38
          7 |         36        0.36       99.74
          8 |          1        0.01       99.75
          9 |         25        0.25      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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