Year	Percent change (Units)
1980	9.482
1981	9.586
1982	-0.050
1983	-4.624
1984	3.513
1985	1.919
1986	-3.930
1987	2.063
1988	1.218
1989	3.625
1990	5.250
1991	3.976
1992	3.569
1993	2.867
1994	4.394
1995	-5.910
1996	6.218
1997	7.199
1998	6.185
1999	2.755
2000	5.029
2001	-0.451
2002	-0.237
2003	1.186
2004	3.565
2005	2.113
2006	4.805
2007	2.078
2008	0.943
2009	-6.295
2010	4.971
2011	3.444
2012	3.553
2013	0.852
2014	2.504
2015	2.702
2016	1.772
2017	1.872
2018	1.972
2019	-0.251
2020	-8.625
2021	5.739
2022	3.949
2023	3.229
2024	2.367
2025	1.438
2026	1.935
2027	2.056
2028	2.061
2029	2.061