Year	Percent change
1980	403.516
1981	47.845
1982	-6.045
1983	-10.257
1984	-6.678
1985	-18.302
1986	-10.141
1987	138.908
1988	-18.608
1989	4.148
1990	21.598
1991	-12.867
1992	30.114
1993	-15.005
1994	-18.645
1995	26.863
1996	-10.972
1997	2.217
1998	-7.287
1999	15.482
2000	4.282
2001	4.629
2002	16.885
2003	-13.726
2004	-4.356
2005	28.619
2006	-23.212
2007	0.29
2008	-1.169
2009	5.103
2010	-11.94
2011	11.939
2012	9.727
2013	2.171
2014	16.817
2015	7.383
2016	0.77
2017	3.839
2018	3.106
2019	3.035
2020	3.047
2021	3.019
2022	2.992
2023	2.947
2024	2.788