Year	Percent change (Units)
1980	-38.140
1981	23.395
1982	5.135
1983	-40.769
1984	-1.539
1985	49.529
1986	32.370
1987	9.041
1988	-3.461
1989	-40.808
1990	92.517
1991	9.727
1992	48.011
1993	-9.497
1994	-48.075
1995	123.129
1996	3.001
1997	1.342
1998	11.482
1999	19.218
2000	-12.115
2001	12.921
2002	29.914
2003	29.898
2004	-2.577
2005	-10.616
2006	9.649
2007	45.878
2008	4.517
2009	7.941
2010	-13.921
2011	-11.570
2012	5.895
2013	34.750
2014	29.097
2015	0.451
2016	5.072
2017	8.317
2018	13.559
2019	-10.813
2020	-1.478
2021	3.406
2022	-14.518
2023	15.288
2024	13.050
2025	7.831
2026	9.174
2027	9.121
2028	7.657
2029	7.129