Year	Percent change (Units)
1980	2.894
1981	4.127
1982	0.063
1983	-0.474
1984	6.346
1985	5.456
1986	2.448
1987	4.893
1988	4.253
1989	4.644
1990	1.513
1991	-0.995
1992	2.584
1993	3.929
1994	4.851
1995	2.959
1996	4.013
1997	4.658
1998	4.708
1999	4.411
2000	3.088
2001	2.638
2002	4.152
2003	3.003
2004	4.121
2005	3.005
2006	2.634
2007	4.369
2008	2.567
2009	1.967
2010	2.439
2011	2.770
2012	3.798
2013	2.232
2014	2.586
2015	2.349
2016	2.720
2017	2.420
2018	2.849
2019	1.815
2020	-2.129
2021	5.554
2022	3.811
2023	2.063
2024	1.461
2025	2.045
2026	2.150
2027	2.202
2028	2.232
2029	2.258