Year	Percent change (Units)
1980	10.340
1981	9.193
1982	2.886
1983	6.015
1984	10.002
1985	0.715
1986	11.104
1987	13.396
1988	8.512
1989	2.277
1990	3.831
1991	5.702
1992	6.235
1993	6.201
1994	6.036
1995	2.374
1996	4.259
1997	5.100
1998	-5.883
1999	2.507
2000	7.663
2001	0.561
2002	1.657
2003	3.056
2004	8.700
2005	7.388
2006	7.033
2007	6.465
2008	2.128
2009	-2.459
2010	6.768
2011	4.815
2012	1.700
2013	3.102
2014	2.762
2015	2.388
2016	2.175
2017	3.796
2018	2.847
2019	-1.672
2020	-6.545
2021	6.454
2022	-3.681
2023	3.215
2024	2.879
2025	2.726
2026	2.599
2027	2.591
2028	2.556
2029	2.561