Year	Percent change (Units)
1980	8.552
1981	-4.588
1982	2.210
1983	4.113
1984	0.918
1985	6.362
1986	3.492
1987	8.790
1988	10.630
1989	9.012
1990	-0.341
1991	-13.319
1992	0.697
1993	1.364
1994	12.811
1995	8.188
1996	7.234
1997	11.880
1998	8.470
1999	4.287
2000	14.862
2001	1.381
2002	4.293
2003	4.108
2004	8.123
2005	11.182
2006	6.590
2007	7.382
2008	7.966
2009	-16.998
2010	6.304
2011	6.207
2012	1.125
2013	0.125
2014	-0.897
2015	1.963
2016	5.721
2017	4.314
2018	5.732
2019	2.364
2020	-6.157
2021	6.132
2022	8.395
2023	-7.385
2024	2.154
2025	3.204
2026	3.327
2027	3.327
2028	3.327
2029	3.327