Year	Percent change (Units)
1980	18.086
1981	1.043
1982	42.901
1983	-4.800
1984	-17.653
1985	-16.245
1986	-5.945
1987	-23.538
1988	-5.240
1989	-7.398
1990	-10.362
1991	24.100
1992	-8.510
1993	-6.358
1994	2.875
1995	35.798
1996	-2.289
1997	55.388
1998	10.792
1999	-10.698
2000	10.487
2001	11.352
2002	2.564
2003	-1.392
2004	8.406
2005	4.375
2006	0.784
2007	9.225
2008	3.134
2009	-18.736
2010	-21.586
2011	41.681
2012	10.305
2013	2.365
2014	-4.892
2015	20.195
2016	-0.817
2017	-9.430
2018	-10.090
2019	-14.152
2020	-9.644
2021	0.215
2022	10.847
2023	-11.991
2024	2.737
2025	3.804
2026	2.063
2027	1.527
2028	1.509
2029	3.079