Year	Percent change (Units)
1980	5.700
1981	5.300
1982	4.200
1983	3.000
1984	4.600
1985	1.800
1986	5.300
1987	4.700
1988	2.400
1989	-0.500
1990	-9.100
1991	-10.755
1992	-8.426
1993	-11.625
1994	-3.665
1995	-1.601
1996	5.205
1997	-14.115
1998	3.789
1999	-8.396
2000	4.587
2001	3.824
2002	5.872
2003	5.237
2004	6.510
2005	7.056
2006	6.803
2007	6.654
2008	6.130
2009	-3.347
2010	1.555
2011	2.090
2012	0.749
2013	-0.543
2014	0.949
2015	3.398
2016	3.027
2017	2.746
2018	2.695
2019	4.035
2020	-3.966
2021	7.662
2022	3.926
2023	1.846
2024	2.737
2025	2.925
2026	2.930
2027	2.650
2028	2.740
2029	2.585