Year	Percent change (Units)
1980	9.337
1981	7.748
1982	-2.743
1983	2.302
1984	-2.056
1985	4.619
1986	13.059
1987	1.528
1988	8.395
1989	10.297
1990	8.059
1991	5.424
1992	0.777
1993	0.841
1994	1.851
1995	8.318
1996	9.822
1997	8.697
1998	18.043
1999	14.945
2000	20.369
2001	1.085
2002	-3.716
2003	7.192
2004	4.593
2005	0.934
2006	13.214
2007	15.364
2008	1.641
2009	-20.197
2010	-3.082
2011	-9.599
2012	-5.585
2013	-3.636
2014	6.734
2015	8.038
2016	3.001
2017	4.951
2018	6.619
2019	1.160
2020	-1.454
2021	8.975
2022	3.413
2023	-1.463
2024	2.497
2025	2.949
2026	2.427
2027	2.283
2028	2.207
2029	2.088