Year	Percent change (Units)
1980	6.300
1981	8.073
1982	9.357
1983	8.669
1984	5.637
1985	4.094
1986	0.300
1987	-0.100
1988	1.400
1989	3.400
1990	3.700
1991	3.100
1992	3.200
1993	3.600
1994	2.200
1995	1.900
1996	1.156
1997	1.371
1998	0.972
1999	1.021
2000	3.782
2001	2.404
2002	2.056
2003	2.528
2004	3.244
2005	3.761
2006	2.962
2007	2.655
2008	4.092
2009	0.007
2010	2.795
2011	3.728
2012	2.888
2013	1.699
2014	0.694
2015	0.059
2016	0.043
2017	2.112
2018	2.018
2019	1.651
2020	0.006
2021	3.468
2022	8.150
2023	2.929
2024	2.539
2025	3.095
2026	2.064
2027	2.015
2028	1.975
2029	2.059