Year	Percent change (Units)
1980	3.568
1981	4.723
1982	1.424
1983	2.586
1984	2.210
1985	4.451
1986	3.551
1987	7.490
1988	3.564
1989	1.419
1990	6.633
1991	4.618
1992	7.155
1993	3.771
1994	7.011
1995	9.654
1996	5.870
1997	3.755
1998	4.064
1999	3.323
2000	8.626
2001	0.171
2002	-0.121
2003	1.465
2004	4.680
2005	4.215
2006	5.581
2007	6.023
2008	3.286
2009	1.108
2010	5.633
2011	5.563
2012	2.541
2013	4.231
2014	3.885
2015	2.314
2016	4.367
2017	4.273
2018	4.075
2019	3.785
2020	-1.465
2021	9.344
2022	6.470
2023	2.003
2024	1.609
2025	5.435
2026	3.100
2027	3.405
2028	3.562
2029	3.559