Frequencies for first 10,000 rows of impacts variable in vehicle dataset : VEHICLE | ROLE | Freq. Percent Cum. ------------+----------------------------------- 0 | 621 6.21 6.21 1 | 6,155 61.55 67.76 2 | 2,534 25.34 93.10 3 | 619 6.19 99.29 9 | 71 0.71 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 18 Apr 2016