Year	Percent change (Units)
1980	-0.800
1981	-22.400
1982	9.600
1983	-24.400
1984	-23.100
1985	27.000
1986	-24.600
1987	13.700
1988	-9.800
1989	-3.300
1990	-18.900
1991	-14.400
1992	-4.700
1993	1.387
1994	9.317
1995	-9.800
1996	18.584
1997	-8.000
1998	31.783
1999	-14.658
2000	7.461
2001	6.865
2002	3.209
2003	1.140
2004	2.885
2005	13.080
2006	-6.020
2007	7.538
2008	28.746
2009	36.282
2010	9.968
2011	4.690
2012	14.291
2013	2.621
2014	-13.626
2015	6.166
2016	-13.381
2017	9.636
2018	8.650
2019	9.513
2020	2.845
2021	1.126
2022	-2.014
2023	-1.731
2024	14.322
2025	9.061
2026	5.733
2027	5.885
2028	5.579
2029	5.671