Year	Percent change (Units)
1980	3.030
1981	0.520
1982	-29.336
1983	-6.946
1984	-10.342
1985	15.874
1986	2.170
1987	-9.410
1988	-8.573
1989	-4.178
1990	-2.865
1991	-15.797
1992	12.962
1993	19.617
1994	5.893
1995	4.188
1996	2.921
1997	4.055
1998	4.613
1999	-5.670
2000	-6.364
2001	3.514
2002	-1.299
2003	-3.868
2004	-2.101
2005	-4.517
2006	1.092
2007	2.666
2008	-0.491
2009	6.106
2010	1.365
2011	0.480
2012	6.519
2013	-2.097
2014	-2.929
2015	12.309
2016	4.958
2017	0.354
2018	16.875
2019	10.017
2020	26.083
2021	16.193
2022	6.682
2023	14.694
2024	28.330
2025	-1.330
2026	-0.598
2027	9.477
2028	-4.517
2029	18.951