Year	Percent change
1980	37
1981	21.488
1982	-53.335
1983	-37.068
1984	38.222
1985	16.564
1986	-12.636
1987	9.585
1988	61.165
1989	18.389
1990	18.726
1991	18.251
1992	22.579
1993	16.596
1994	20.831
1995	-15.249
1996	18.784
1997	24.637
1998	15.825
1999	11.947
2000	20.679
2001	-0.592
2002	1.14
2003	2.582
2004	6.733
2005	5.125
2006	8.632
2007	4.889
2008	4.124
2009	-16.691
2010	18.375
2011	5.205
2012	5.642
2013	2.097
2014	6.23
2015	6.21
2016	2.941
2017	6.149
2018	6.669
2019	3.087
2020	3.524
2021	4.15
2022	4.411
2023	4.455
2024	4.503