Year	Percent change (Units)
1980	-6.123
1981	-9.056
1982	-1.014
1983	0.485
1984	1.980
1985	5.826
1986	4.790
1987	0.509
1988	2.871
1989	5.819
1990	-6.444
1991	-2.443
1992	4.135
1993	1.683
1994	6.390
1995	6.556
1996	7.274
1997	0.803
1998	1.100
1999	-0.636
2000	5.093
2001	7.390
2002	5.652
2003	5.213
2004	3.087
2005	6.639
2006	2.132
2007	0.486
2008	3.556
2009	-0.536
2010	2.533
2011	3.849
2012	-3.732
2013	0.107
2014	0.660
2015	3.850
2016	7.984
2017	1.406
2018	-0.610
2019	4.453
2020	-3.108
2021	-7.077
2022	-5.308
2023	7.990
2024	5.350
2025	3.441
2026	2.685
2027	2.171
2028	2.000
2029	2.000