Year	Percent change (Units)
1980	-8.625
1981	-5.725
1982	-6.306
1983	1.535
1984	1.337
1985	0.616
1986	0.190
1987	2.513
1988	1.878
1989	0.962
1990	4.831
1991	1.498
1992	7.021
1993	5.817
1994	4.692
1995	4.733
1996	0.816
1997	3.136
1998	2.652
1999	2.164
2000	1.126
2001	0.877
2002	1.577
2003	1.565
2004	0.889
2005	2.709
2006	4.366
2007	1.846
2008	2.096
2009	-2.053
2010	2.096
2011	3.801
2012	2.834
2013	2.235
2014	1.704
2015	2.400
2016	2.515
2017	2.262
2018	2.445
2019	2.432
2020	-7.901
2021	11.904
2022	2.799
2023	3.498
2024	3.000
2025	2.300
2026	2.300
2027	2.300
2028	2.300
2029	2.300