Year	Percent change (Units)
1980	-0.100
1981	0.000
1982	0.000
1983	0.000
1984	0.000
1985	0.000
1986	0.000
1987	0.000
1988	0.000
1989	0.000
1990	7.917
1991	6.505
1992	-4.988
1993	11.675
1994	19.112
1995	16.601
1996	10.854
1997	-10.009
1998	-2.046
1999	-5.215
2000	-4.456
2001	17.818
2002	15.793
2003	4.890
2004	1.938
2005	20.355
2006	-10.058
2007	16.327
2008	5.171
2009	-4.797
2010	7.047
2011	4.110
2012	3.514
2013	-7.644
2014	11.889
2015	-5.032
2016	4.076
2017	-2.631
2018	2.362
2019	1.126
2020	9.476
2021	4.479
2022	-3.104
2023	-3.115
2024	9.229
2025	8.007
2026	8.529
2027	6.693
2028	6.149
2029	6.470