Year	Percent change (Units)
1981	-6.058
1982	0.039
1983	3.916
1984	5.307
1985	6.464
1986	4.245
1987	3.718
1988	3.213
1989	7.802
1990	3.976
1991	6.335
1992	2.851
1993	0.396
1994	9.032
1995	9.821
1996	5.323
1997	11.130
1998	8.392
1999	9.882
2000	11.112
2001	2.627
2002	0.353
2003	1.981
2004	6.334
2005	5.425
2006	7.605
2007	7.901
2008	-0.759
2009	-7.612
2010	8.552
2011	3.877
2012	2.166
2013	2.326
2014	3.271
2015	14.883
2016	-1.977
2017	6.174
2018	4.714
2019	3.258
2020	-4.671
2021	6.426
2022	3.797
2023	-0.757
2024	0.849
2025	3.000
2026	3.651
2027	3.603
2028	3.603
2029	3.603