Year	Percent change (Units)
1980	2.702
1981	4.853
1982	-1.126
1983	4.742
1984	6.771
1985	2.114
1986	-0.967
1987	2.795
1988	8.462
1989	9.778
1990	4.146
1991	6.277
1992	5.950
1993	0.395
1994	8.159
1995	8.854
1996	4.268
1997	13.039
1998	8.813
1999	5.112
2000	12.886
2001	3.072
2002	1.997
2003	-0.959
2004	5.358
2005	3.976
2006	5.998
2007	2.791
2008	0.441
2009	-10.898
2010	8.695
2011	6.364
2012	2.842
2013	2.141
2014	3.272
2015	4.646
2016	1.776
2017	4.386
2018	4.527
2019	1.619
2020	-16.904
2021	10.657
2022	7.368
2023	1.481
2024	2.264
2025	3.487
2026	3.561
2027	3.366
2028	3.403
2029	3.230