Year	Percent change (Units)
1980	8.098
1981	5.804
1982	-1.870
1983	4.327
1984	6.527
1985	0.637
1986	1.684
1987	2.757
1988	3.167
1989	2.746
1990	1.653
1991	-7.895
1992	10.379
1993	16.668
1994	13.287
1995	8.751
1996	5.763
1997	14.028
1998	8.872
1999	11.337
2000	16.104
2001	1.822
2002	3.985
2003	-1.009
2004	8.742
2005	6.950
2006	9.814
2007	8.986
2008	6.601
2009	-20.114
2010	6.182
2011	2.028
2012	0.233
2013	0.574
2014	-1.952
2015	0.392
2016	3.893
2017	8.822
2018	1.503
2019	6.675
2020	-7.764
2021	6.160
2022	3.615
2023	-1.779
2024	0.095
2025	3.200
2026	3.341
2027	3.271
2028	3.235
2029	3.200