Year	Percent change (Units)
1980	2.500
1981	6.320
1982	4.127
1983	-1.510
1984	-5.629
1985	-0.623
1986	9.933
1987	6.462
1988	4.292
1989	1.423
1990	0.838
1991	7.024
1992	5.541
1993	2.750
1994	3.514
1995	8.860
1996	5.465
1997	6.057
1998	8.242
1999	4.235
2000	8.385
2001	10.867
2002	5.941
2003	6.289
2004	5.136
2005	5.648
2006	6.531
2007	5.735
2008	3.847
2009	-2.768
2010	3.858
2011	-3.214
2012	-17.005
2013	1.955
2014	4.661
2015	4.906
2016	4.700
2017	0.768
2018	-2.290
2019	-2.500
2020	-3.630
2021	0.500
2022	-2.500
2023	-18.300
2024	-4.201
2025	5.400
2026	7.400
2027	7.000
2028	5.000
2029	4.500