Year	Percent change (Units)
1980	1.203
1981	-0.408
1982	1.239
1983	1.652
1984	1.698
1985	2.362
1986	3.432
1987	5.709
1988	5.285
1989	5.004
1990	3.847
1991	2.525
1992	0.851
1993	-1.314
1994	2.335
1995	4.122
1996	2.421
1997	3.865
1998	4.469
1999	4.745
2000	5.053
2001	3.932
2002	2.729
2003	2.982
2004	3.125
2005	3.653
2006	4.098
2007	3.607
2008	0.889
2009	-3.766
2010	0.165
2011	-0.814
2012	-2.962
2013	-1.401
2014	1.398
2015	3.837
2016	3.038
2017	2.977
2018	2.283
2019	1.983
2020	-11.165
2021	6.400
2022	5.771
2023	2.501
2024	1.897
2025	2.082
2026	1.820
2027	1.628
2028	1.636
2029	1.617