Year	Percent change (Units)
1980	9.582
1981	-5.893
1982	-1.704
1983	7.095
1984	2.953
1985	16.119
1986	4.161
1987	1.382
1988	-3.919
1989	3.002
1990	0.923
1991	-16.908
1992	-3.066
1993	14.822
1994	2.048
1995	0.905
1996	2.208
1997	1.401
1998	1.124
1999	17.878
2000	10.318
2001	-12.960
2002	10.118
2003	-3.685
2004	7.321
2005	9.215
2006	0.730
2007	6.004
2008	-3.792
2009	-20.955
2010	2.981
2011	-0.069
2012	8.486
2013	-1.302
2014	-3.118
2015	-4.876
2016	4.339
2017	4.947
2018	23.802
2019	6.421
2020	-67.022
2021	90.361
2022	54.154
2023	7.111
2024	6.381
2025	2.937
2026	2.393
2027	2.250
2028	2.201
2029	2.216