Year	Percent change (Units)
1980	4.371
1981	-1.900
1982	-4.900
1983	0.500
1984	3.600
1985	1.100
1986	5.100
1987	2.600
1988	3.500
1989	3.600
1990	-3.300
1991	-3.900
1992	-5.700
1993	0.800
1994	2.000
1995	2.023
1996	3.966
1997	4.740
1998	3.740
1999	0.326
2000	4.453
2001	-2.367
2002	0.791
2003	2.171
2004	1.407
2005	3.965
2006	5.669
2007	2.202
2008	0.698
2009	-5.076
2010	-2.288
2011	-0.673
2012	-0.450
2013	-1.411
2014	-0.126
2015	2.446
2016	2.485
2017	-0.686
2018	-0.675
2019	0.332
2020	-12.713
2021	-1.324
2022	13.800
2023	4.400
2024	3.700
2025	2.800
2026	2.300
2027	2.000
2028	2.000
2029	2.000