Summary statistics for veh_aux dataset : by Jean Roth , jroth@nber.org , 18 Apr 2016 Variable | Obs Mean Std. Dev. Min Max -------------+--------------------------------------------------------- year | 60,870 1989 0 1989 1989 veh_no | 60,870 1.415936 .9297857 1 43 st_case | 60,870 272161.1 160198.7 10001 560114 a_body | 60,870 2.348431 2.152696 1 9 a_imp1 | 60,870 2.692328 1.371863 1 7 -------------+--------------------------------------------------------- a_imp2 | 60,870 2.770215 1.432674 1 7 a_vroll | 60,870 1.832118 .3737649 1 2 a_lic_s | 60,870 1.324051 .7787393 1 4 a_lic_c | 60,870 1.193018 .4807356 1 3 a_cdl_s | 60,870 3 0 3 3 -------------+--------------------------------------------------------- a_mc_l_s | 60,870 3.866798 .5796836 1 4 a_spveh | 60,870 1.770445 .42055 1 2 a_sbus | 60,870 2.996287 .0853262 1 3 a_mod_yr | 60,870 2161.498 1185.733 1922 9999 a_drdis | 60,870 1.929522 .2559531 1 2 -------------+--------------------------------------------------------- a_drdro | 60,870 1.977624 .1479028 1 2 by Jean Roth , jroth@nber.org , 18 Apr 2016