Year	Percent change (Units)
1980	0.221
1981	-5.353
1982	-2.645
1983	-1.329
1984	2.666
1985	10.077
1986	-3.690
1987	4.649
1988	8.170
1989	2.181
1990	-0.434
1991	-1.545
1992	5.491
1993	10.379
1994	2.486
1995	10.937
1996	7.204
1997	5.296
1998	3.246
1999	1.261
2000	8.314
2001	2.393
2002	0.989
2003	0.109
2004	2.834
2005	8.567
2006	7.463
2007	7.829
2008	1.550
2009	-17.024
2010	7.718
2011	3.008
2012	1.112
2013	3.733
2014	3.646
2015	3.060
2016	0.407
2017	-0.273
2018	2.748
2019	-3.313
2020	-11.968
2021	9.090
2022	7.390
2023	3.530
2024	3.470
2025	3.565
2026	3.685
2027	3.685
2028	3.685
2029	3.685