Year	Percent change (Units)
1981	8.110
1982	6.500
1983	11.600
1984	20.300
1985	5.100
1986	-16.000
1987	-4.700
1988	14.900
1989	-4.802
1990	3.413
1991	2.100
1992	-6.800
1993	31.400
1994	15.290
1995	10.000
1996	10.500
1997	0.620
1998	3.500
1999	3.300
2000	13.046
2001	0.702
2002	12.556
2003	-11.864
2004	9.219
2005	-8.070
2006	7.956
2007	1.658
2008	9.658
2009	4.738
2010	-2.156
2011	10.730
2012	2.064
2013	0.897
2014	3.705
2015	2.014
2016	-4.576
2017	2.919
2018	4.339
2019	-1.686
2020	5.701
2021	1.182
2022	3.293
2023	7.060
2024	2.950
2025	2.950
2026	2.950
2027	2.950
2028	2.950
2029	2.950