1969 = 1.16
1977 = 1.59
1983 = 1.68
1990 = 1.77
1995 = 1.78
2001 = 1.90
1969 = 3.16
1977 = 2.83
1983 = 2.69
1990 = 2.56
1995 = 2.63
2001 = 2.58
Back to April 2003 edition of Highway Information Quarterly newsletter.