Year	Percent
1973	4.111
1977	3.705
1978	2.87
1979	4.017
1981	1.355
1982	1.511
1983	1.663
1984	1.79
1985	7.326
1986	1.994
1987	5.831
1988	3.163
1991	1.741
1992	1.88
1993	0.6452
1994	0.7398
1995	0.7397
1998	2.288
1999	2.104
2000	2.109
2001	2.32
2002	2.014
2003	1.673
2004	1.924
2005	2.23
2006	2.302
2007	2.714