Year	Percent change
1980	21.616
1981	14.216
1982	-17.848
1983	-18.681
1984	21.473
1985	-14.699
1986	-5.324
1987	3.961
1988	23.943
1989	-1.54
1990	-4.265
1991	0.38
1992	5.539
1993	6.695
1994	18.918
1995	19.676
1996	11.852
1997	6.732
1998	1.223
1999	-9.289
2000	7.733
2001	0.155
2002	5.614
2003	4.649
2004	17.895
2005	11.776
2006	19.888
2007	10.046
2008	4.079
2009	-21.394
2010	9.743
2011	14.408
2012	6.437
2013	6.194
2014	0.014
2015	5.469
2016	-4.016
2017	2.276
2018	2.546
2019	3.032
2020	3.298
2021	3.312
2022	3.312
2023	3.312
2024	3.312