Frequencies for first 10,000 rows of pcrash4 variable in vehicle dataset :

pre- impact |
  stability |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |         66        0.66        0.66
          1 |      7,682       76.82       77.48
          2 |        713        7.13       84.61
          3 |        305        3.05       87.66
          4 |        361        3.61       91.27
          5 |         45        0.45       91.72
          7 |         40        0.40       92.12
          9 |        788        7.88      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 22 Oct 2016