Year	Percent change (Units)
1980	8.834
1981	11.865
1982	-1.529
1983	5.162
1984	15.911
1985	5.167
1986	-2.540
1987	0.075
1988	4.599
1989	4.852
1990	5.021
1991	2.070
1992	12.744
1993	-2.306
1994	1.568
1995	3.311
1996	2.886
1997	11.605
1998	-2.028
1999	3.517
2000	13.564
2001	-7.993
2002	8.170
2003	9.315
2004	14.305
2005	7.774
2006	10.743
2007	8.749
2008	1.558
2009	-25.538
2010	28.307
2011	0.038
2012	0.566
2013	-0.713
2014	6.391
2015	3.211
2016	1.618
2017	6.619
2018	3.760
2019	-1.458
2020	-11.595
2021	11.872
2022	5.283
2023	3.021
2024	3.281
2025	1.715
2026	2.456
2027	1.755
2028	1.577
2029	1.467