Year	Percent change (Units)
1980	4.353
1981	-8.907
1982	1.698
1983	-4.395
1984	4.753
1985	-8.332
1986	-2.115
1987	8.809
1988	19.195
1989	14.134
1990	7.792
1991	1.619
1992	19.158
1993	-25.485
1994	8.727
1995	-17.329
1996	7.872
1997	0.885
1998	1.909
1999	3.308
2000	12.546
2001	-0.193
2002	-0.355
2003	-0.976
2004	6.946
2005	1.570
2006	5.702
2007	10.463
2008	12.508
2009	-15.324
2010	10.796
2011	-2.592
2012	-3.633
2013	-4.556
2014	7.719
2015	8.062
2016	10.164
2017	14.303
2018	4.325
2019	9.503
2020	3.245
2021	15.364
2022	18.282
2023	5.100
2024	-2.898
2025	1.955
2026	2.428
2027	2.718
2028	2.659
2029	2.618