Year	Percent change
1980	19.332
1981	18.4
1982	14.274
1983	5.987
1984	9.453
1985	16.818
1986	36.187
1987	71.429
1988	30
1989	15.385
1990	11.111
1991	9
1992	11.1
1993	13.2
1994	15.328
1995	7.722
1996	8.872
1997	1.889
1998	-0.953
1999	-3.7
2000	-3.9
2001	3.401
2002	-0.518
2003	5.797
2004	4.433
2005	7.24
2006	10.39
2007	4.677
2008	15.153
2009	2.804
2010	4.398