Frequencies for first 10,000 rows of cf2 variable in accident dataset :

    Related |
Factors (2) |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,949       99.49       99.49
          6 |          1        0.01       99.50
         14 |          8        0.08       99.58
         15 |          1        0.01       99.59
         17 |          1        0.01       99.60
         18 |          1        0.01       99.61
         19 |          7        0.07       99.68
         20 |          4        0.04       99.72
         23 |         13        0.13       99.85
         99 |         15        0.15      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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