Year	Percent change
1980	18.774
1981	13.736
1982	-17.367
1983	-16.092
1984	19.799
1985	-14.036
1986	-2.452
1987	3.494
1988	21.91
1989	0.317
1990	-5.837
1991	2.143
1992	5.347
1993	7.018
1994	16.093
1995	16.79
1996	8.711
1997	5.385
1998	2.014
1999	-8.362
2000	5.338
2001	0.25
2002	5.341
2003	8.084
2004	15.509
2005	10.879
2006	18.261
2007	9.366
2008	2.809
2009	-17.66
2010	10.794
2011	11.912
2012	4.22
2013	5.014
2014	-0.564
2015	5.387
2016	-3.779
2017	1.597
2018	2.546
2019	3.032
2020	3.298
2021	3.312
2022	3.312
2023	3.312
2024	3.312