Year	Percent change (Units)
1980	5.653
1981	1.943
1982	-20.730
1983	-16.051
1984	-4.661
1985	-9.794
1986	17.013
1987	-6.632
1988	13.109
1989	-0.503
1990	15.193
1991	15.008
1992	3.987
1993	-1.364
1994	0.559
1995	0.212
1996	2.637
1997	1.104
1998	2.893
1999	-3.763
2000	5.625
2001	-1.211
2002	-2.819
2003	11.242
2004	7.958
2005	5.574
2006	2.788
2007	1.847
2008	6.250
2009	-2.059
2010	5.040
2011	10.994
2012	5.409
2013	2.535
2014	3.811
2015	4.509
2016	1.885
2017	0.911
2018	3.199
2019	1.098
2020	-3.582
2021	5.075
2022	7.486
2023	-0.755
2024	2.554
2025	5.968
2026	3.977
2027	3.500
2028	2.996
2029	3.520