Year	Percent
1990	1.53
1991	1.99
1992	2.17
1993	2
1994	1.67
1995	1.37
1996	1.15
1997	0.98
1998	0.85
1999	0.74
2000	0.64
2001	0.56
2002	0.49
2003	0.43
2004	0.37
2005	0.32
2006	0.27
2007	0.23
2008	0.2
2009	0.17