Year	Percent change (Units)
1980	-5.400
1981	11.340
1982	22.636
1983	14.187
1984	5.837
1985	-4.463
1986	4.557
1987	9.472
1988	5.674
1989	5.760
1990	5.079
1991	5.111
1992	4.953
1993	9.268
1994	9.743
1995	25.474
1996	17.322
1997	8.662
1998	8.228
1999	6.821
2000	15.270
2001	1.837
2002	2.739
2003	-1.772
2004	5.762
2005	6.372
2006	8.698
2007	2.520
2008	-2.055
2009	-10.104
2010	23.080
2011	9.287
2012	7.918
2013	2.702
2014	7.572
2015	7.029
2016	3.067
2017	3.198
2018	6.527
2019	1.164
2020	-7.019
2021	7.217
2022	8.682
2023	-6.937
2024	-0.492
2025	2.268
2026	2.917
2027	3.087
2028	3.092
2029	3.090