Year	Percent change (Units)
1980	-6.280
1981	9.749
1982	4.126
1983	6.386
1984	-0.828
1985	-0.934
1986	9.224
1987	18.962
1988	-2.936
1989	-4.904
1990	8.856
1991	15.970
1992	8.783
1993	14.070
1994	13.196
1995	9.368
1996	7.192
1997	4.194
1998	2.120
1999	15.548
2000	11.959
2001	-5.441
2002	-1.245
2003	-0.785
2004	11.847
2005	3.487
2006	3.420
2007	11.126
2008	2.471
2009	-13.764
2010	15.089
2011	11.250
2012	2.153
2013	1.002
2014	2.327
2015	0.115
2016	10.270
2017	4.593
2018	7.358
2019	3.901
2020	-7.950
2021	21.103
2022	12.031
2023	-6.647
2024	-3.318
2025	13.871
2026	7.379
2027	4.400
2028	4.600
2029	4.800