Year	Percent change (Units)
1980	10.011
1981	6.400
1982	2.538
1983	-2.074
1984	-7.358
1985	-3.971
1986	7.644
1987	2.561
1988	1.589
1989	1.564
1990	10.011
1991	4.600
1992	0.956
1993	1.136
1994	-0.655
1995	-1.131
1996	0.496
1997	-0.360
1998	0.429
1999	0.512
2000	-1.197
2001	-0.841
2002	-0.286
2003	0.185
2004	0.757
2005	1.861
2006	3.204
2007	5.892
2008	12.560
2009	3.537
2010	3.256
2011	4.061
2012	2.941
2013	1.331
2014	1.197
2015	0.142
2016	0.888
2017	1.458
2018	0.704
2019	0.472
2020	-0.395
2021	1.664
2022	2.512
2023	0.947
2024	1.300
2025	1.500
2026	2.000
2027	2.000
2028	2.000
2029	2.000