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

UNDERRIDE/O |
    VERRIDE |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,920       99.20       99.20
          1 |         14        0.14       99.34
          2 |          3        0.03       99.37
          3 |          8        0.08       99.45
          4 |          8        0.08       99.53
          6 |          1        0.01       99.54
          7 |         17        0.17       99.71
          8 |          2        0.02       99.73
          9 |         27        0.27      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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