Year	Percent change (Units)
1980	0.926
1981	-0.956
1982	2.659
1983	2.172
1984	8.056
1985	5.502
1986	4.359
1987	6.109
1988	2.110
1989	5.872
1990	6.288
1991	1.076
1992	2.464
1993	3.794
1994	9.927
1995	9.856
1996	7.642
1997	13.518
1998	0.337
1999	2.452
2000	9.978
2001	2.875
2002	0.872
2003	-1.642
2004	1.781
2005	7.681
2006	14.701
2007	-9.007
2008	0.580
2009	-10.427
2010	10.382
2011	6.533
2012	-0.980
2013	-0.738
2014	1.362
2015	3.522
2016	0.858
2017	7.051
2018	0.470
2019	2.097
2020	-12.267
2021	1.097
2022	9.674
2023	-8.048
2024	-0.923
2025	0.450
2026	1.192
2027	1.865
2028	1.524
2029	1.459