Year	Percent change (Units)
1980	6.621
1981	5.361
1982	-0.383
1983	-1.847
1984	5.099
1985	-1.212
1986	0.018
1987	2.101
1988	4.200
1989	2.395
1990	-0.318
1991	-1.018
1992	-2.137
1993	1.234
1994	3.200
1995	3.100
1996	4.300
1997	2.600
1998	0.500
1999	2.400
2000	4.200
2001	2.700
2002	3.700
2003	2.949
2004	4.555
2005	5.277
2006	5.604
2007	5.360
2008	3.191
2009	-1.538
2010	3.040
2011	3.169
2012	2.396
2013	2.485
2014	1.414
2015	1.322
2016	0.665
2017	1.158
2018	1.557
2019	0.260
2020	-5.963
2021	4.703
2022	1.910
2023	0.602
2024	0.879
2025	1.213
2026	1.375
2027	1.400
2028	1.400
2029	1.400