Year	Percent change (Units)
1980	3.170
1981	0.798
1982	1.039
1983	1.887
1984	4.730
1985	5.596
1986	9.983
1987	3.951
1988	8.464
1989	9.798
1990	5.320
1991	8.645
1992	1.819
1993	4.201
1994	3.821
1995	1.432
1996	1.515
1997	5.937
1998	6.492
1999	8.421
2000	8.442
2001	3.074
2002	3.225
2003	2.619
2004	4.231
2005	2.482
2006	6.016
2007	8.099
2008	-0.302
2009	-3.239
2010	3.760
2011	1.044
2012	1.650
2013	3.172
2014	2.623
2015	2.269
2016	4.978
2017	1.317
2018	1.219
2019	2.916
2020	-0.910
2021	7.169
2022	1.380
2023	-1.095
2024	1.262
2025	2.905
2026	2.521
2027	2.340
2028	2.315
2029	2.300