Year	Percent change (Units)
1980	7.400
1981	5.522
1982	-0.482
1983	4.674
1984	5.731
1985	5.668
1986	-1.453
1987	6.701
1988	0.071
1989	2.579
1990	7.075
1991	4.138
1992	8.009
1993	2.477
1994	3.628
1995	2.671
1996	6.855
1997	5.725
1998	4.963
1999	6.017
2000	4.300
2001	3.796
2002	1.323
2003	4.702
2004	6.236
2005	3.487
2006	5.244
2007	6.710
2008	4.238
2009	3.043
2010	3.511
2011	-2.047
2012	4.217
2013	2.430
2014	3.090
2015	0.968
2016	1.117
2017	2.238
2018	2.625
2019	1.588
2020	-8.592
2021	4.605
2022	2.603
2023	0.425
2024	1.878
2025	1.812
2026	1.673
2027	1.439
2028	1.302
2029	1.224