Year	Percent change (Units)
1980	-10.962
1981	21.239
1982	5.199
1983	-9.443
1984	20.440
1985	4.346
1986	-10.577
1987	-3.891
1988	3.360
1989	10.286
1990	18.074
1991	4.875
1992	10.292
1993	-1.365
1994	-1.120
1995	11.019
1996	-4.534
1997	1.876
1998	18.990
1999	4.933
2000	7.983
2001	10.470
2002	20.866
2003	5.898
2004	6.181
2005	12.059
2006	4.985
2007	19.423
2008	12.612
2009	-1.586
2010	-2.615
2011	9.216
2012	2.288
2013	-6.821
2014	2.420
2015	-3.263
2016	17.587
2017	5.456
2018	4.344
2019	3.717
2020	-7.776
2021	11.754
2022	-4.405
2023	-3.292
2024	4.738
2025	4.349
2026	3.735
2027	3.304
2028	3.525
2029	2.597