Year	Percent change (Units)
1980	13.383
1981	10.829
1982	4.128
1983	2.556
1984	4.197
1985	1.421
1986	7.073
1987	6.308
1988	7.817
1989	-0.191
1990	5.419
1991	1.346
1992	2.030
1993	2.162
1994	0.034
1995	3.030
1996	3.105
1997	2.185
1998	3.774
1999	0.355
2000	2.340
2001	-0.063
2002	-2.829
2003	6.353
2004	3.051
2005	0.656
2006	4.659
2007	6.354
2008	7.121
2009	-1.170
2010	0.673
2011	-0.224
2012	-1.059
2013	-1.000
2014	4.754
2015	-2.732
2016	2.764
2017	-6.619
2018	3.548
2019	5.502
2020	-16.605
2021	6.892
2022	5.648
2023	4.726
2024	4.589
2025	4.256
2026	3.280
2027	2.923
2028	2.916
2029	2.400