Year	Percent change (Units)
1980	7.258
1981	9.051
1982	8.061
1983	6.555
1984	4.130
1985	-1.967
1986	0.369
1987	5.437
1988	5.852
1989	9.721
1990	3.979
1991	3.527
1992	11.062
1993	8.332
1994	12.514
1995	13.302
1996	5.514
1997	14.030
1998	11.358
1999	7.981
2000	11.398
2001	2.413
2002	17.719
2003	16.239
2004	27.034
2005	17.903
2006	15.956
2007	18.473
2008	7.139
2009	-5.360
2010	27.255
2011	12.865
2012	0.160
2013	4.878
2014	4.274
2015	-5.033
2016	6.677
2017	10.180
2018	4.908
2019	-2.149
2020	-6.521
2021	19.741
2022	9.772
2023	-0.873
2024	3.890
2025	4.099
2026	3.912
2027	3.859
2028	3.820
2029	3.760