Year	Percent
1985	19.16
1986	7.513
1987	14.52
1988	12.53
1989	10.39
1990	14.9
1991	12.03
1992	10.58
1994	12.42
1995	22.57
1996	22.57
1998	20.45
1999	18.95
2000	21.53
2001	20.89
2002	32.07
2003	30.17
2004	31.15
2005	31.5
2006	18.01
2007	23.36