Year	Percent change (Units)
1980	-4.613
1981	-1.237
1982	-12.874
1983	2.917
1984	2.039
1985	5.404
1986	10.712
1987	-6.504
1988	23.691
1989	-8.692
1990	-3.259
1991	-4.967
1992	1.990
1993	23.131
1994	8.861
1995	8.300
1996	16.300
1997	2.800
1998	7.893
1999	-15.165
2000	20.300
2001	10.182
2002	4.050
2003	11.648
2004	10.632
2005	-0.434
2006	1.150
2007	3.948
2008	-1.018
2009	-19.163
2010	19.518
2011	8.491
2012	10.912
2013	1.065
2014	2.381
2015	3.595
2016	0.749
2017	4.853
2018	0.232
2019	4.170
2020	-14.578
2021	22.464
2022	0.200
2023	-4.064
2024	2.112
2025	2.911
2026	3.379
2027	3.426
2028	3.399
2029	3.200
