Year	Percent change
1980	-38.14
1981	23.395
1982	5.135
1983	-40.769
1984	-1.539
1985	49.529
1986	32.37
1987	9.041
1988	-3.461
1989	-40.808
1990	92.517
1991	9.727
1992	48.011
1993	-9.497
1994	-48.075
1995	123.129
1996	3.001
1997	1.342
1998	11.482
1999	19.213
2000	-12.13
2001	12.922
2002	29.814
2003	29.992
2004	8.589
2005	3.706
2006	12.11
2007	84.389
2008	26.554
2009	-6.452
2010	10.243
2011	7.344
2012	7.031
2013	35.061
2014	23.621
2015	-13.44
2016	2.339
2017	29.767
2018	24.025
2019	20.089
2020	18.424
2021	16.159
2022	16.605
2023	13.426
2024	10.961