Year	Percent change
1980	-44.338
1981	48.945
1982	11.543
1983	-11.398
1984	9.921
1985	12.6
1986	-12.629
1987	8.917
1988	1.766
1989	-10.015
1990	0.413
1991	22.903
1992	5.976
1993	-19.221
1994	-20.668
1995	28.289
1996	-49.669
1997	64.512
1998	-23.443
1999	5.611
2000	5.329
2001	5.001
2002	-14.395
2003	38.579
2004	0.748
2005	22.479
2006	-13.167
2007	12.02
2008	41.616
2009	-13.838
2010	33.917
2011	14.971
2012	12.883
2013	14.586
2014	-12.373
2015	-4.046
2016	0.459
2017	-1.354
2018	5.128
2019	4.976
2020	6.016
2021	6.186
2022	6.102
2023	6.698
2024	7.15