Year	Percent change (Units)
1980	12.303
1981	5.698
1982	-6.617
1983	11.053
1984	1.494
1985	22.051
1986	123.564
1987	-41.893
1988	36.058
1989	4.848
1990	-10.515
1991	3.304
1992	1.870
1993	4.480
1994	-14.827
1995	2.316
1996	2.995
1997	12.084
1998	22.450
1999	-24.535
2000	-17.424
2001	-2.371
2002	6.872
2003	0.025
2004	1.996
2005	-6.985
2006	16.577
2007	-12.098
2008	2.309
2009	44.726
2010	-2.141
2011	-0.435
2012	-1.039
2013	18.102
2014	7.223
2015	20.083
2016	29.518
2017	-19.900
2018	-19.711
2019	7.210
2020	10.181
2021	-13.413
2022	-6.841
2023	1.774
2024	10.288
2025	4.110
2026	3.044
2027	2.748
2028	2.680
2029	2.488