Year	Percent change (Units)
1980	18.889
1981	12.966
1982	4.834
1983	5.124
1984	2.112
1985	1.273
1986	0.550
1987	3.438
1988	2.115
1989	3.476
1990	9.149
1991	2.292
1992	3.073
1993	4.534
1994	0.000
1995	3.565
1996	3.614
1997	0.831
1998	3.295
1999	-1.808
2000	1.408
2001	1.504
2002	-0.450
2003	2.790
2004	1.260
2005	3.900
2006	4.810
2007	8.340
2008	9.380
2009	-2.210
2010	0.900
2011	4.738
2012	1.037
2013	0.000
2014	0.093
2015	-2.050
2016	0.951
2017	3.016
2018	1.372
2019	0.451
2020	-0.988
2021	3.448
2022	6.667
2023	4.102
2024	1.998
2025	1.998
2026	1.998
2027	1.998
2028	1.998
2029	1.998