Year	Percent change (Units)
1980	4.402
1981	2.811
1982	0.946
1983	0.208
1984	-1.559
1985	-3.071
1986	-3.173
1987	-1.589
1988	0.908
1989	1.000
1990	2.079
1991	4.559
1992	-0.371
1993	0.838
1994	0.646
1995	5.046
1996	0.873
1997	-0.433
1998	-0.174
1999	-1.208
2000	-1.731
2001	-0.587
2002	0.591
2003	0.294
2004	0.439
2005	1.166
2006	2.464
2007	7.312
2008	5.372
2009	3.482
2010	3.725
2011	2.549
2012	3.615
2013	2.519
2014	1.904
2015	1.231
2016	0.969
2017	-1.113
2018	1.910
2019	-0.182
2020	5.329
2021	1.243
2022	2.037
2023	0.382
2024	2.257
2025	2.033
2026	2.004
2027	2.000
2028	2.000
2029	1.996