Year	Percent change (Units)
1980	7.100
1981	-2.900
1982	6.300
1983	6.800
1984	2.400
1985	4.100
1986	2.600
1987	3.700
1988	2.255
1989	2.300
1990	1.052
1991	-4.182
1992	-3.826
1993	0.308
1994	3.149
1995	4.379
1996	4.224
1997	4.946
1998	4.716
1999	7.144
2000	4.149
2001	2.626
2002	2.705
2003	-1.265
2004	0.883
2005	3.395
2006	2.517
2007	1.447
2008	-2.324
2009	-4.175
2010	1.539
2011	0.613
2012	3.499
2013	-2.863
2014	1.847
2015	0.997
2016	-0.763
2017	2.524
2018	2.918
2019	-0.744
2020	-23.508
2021	16.985
2022	14.369
2023	4.304
2024	2.299
2025	1.800
2026	1.600
2027	1.500
2028	1.500
2029	1.500