Year	Percent change
1980	-52.937
1981	21.801
1982	27.678
1983	-13.094
1984	-54.6
1985	134
1986	4.6
1987	-51.694
1988	99.134
1989	-6.49
1990	-10.241
1991	47.968
1992	-7.719
1993	20.197
1994	-16.94
1995	10.312
1996	-10.645
1997	4.517
1998	-28.721
1999	7.404
2000	11.241
2001	-22.051
2002	9.252
2003	-17.267
2004	21.807
2005	21.027
2006	6.52
2007	5.742
2008	-3.103
2009	-4.739
2010	14.004
2011	-1.837
2012	-10.382
2013	18.935
2014	22.736
2015	-8.337
2016	0.565
2017	-0.669
2018	2.389
2019	4.107
2020	4.079
2021	4.088
2022	4.097
2023	4.151
2024	3.621