Year	Percent change (Units)
1980	2.800
1981	-3.189
1982	2.320
1983	-1.248
1984	6.732
1985	1.000
1986	4.841
1987	6.232
1988	9.715
1989	8.711
1990	6.227
1991	2.148
1992	4.585
1993	0.500
1994	8.000
1995	8.400
1996	4.221
1997	8.908
1998	5.561
1999	2.681
2000	12.157
2001	1.409
2002	7.384
2003	0.496
2004	6.923
2005	4.986
2006	5.253
2007	5.582
2008	-2.067
2009	-12.226
2010	7.079
2011	4.947
2012	-1.372
2013	0.743
2014	1.947
2015	0.993
2016	5.325
2017	-0.055
2018	1.330
2019	-0.383
2020	-6.619
2021	15.292
2022	5.426
2023	-2.763
2024	-0.503
2025	3.625
2026	3.919
2027	3.874
2028	3.862
2029	3.672