Year	Percent change (Units)
1980	8.541
1981	8.189
1982	3.918
1983	1.037
1984	2.604
1985	0.492
1986	-1.381
1987	0.483
1988	1.523
1989	2.294
1990	3.450
1991	3.440
1992	2.244
1993	2.292
1994	3.095
1995	1.725
1996	1.379
1997	2.023
1998	-0.271
1999	0.023
2000	1.349
2001	1.014
2002	-0.391
2003	0.487
2004	1.671
2005	0.469
2006	0.963
2007	2.105
2008	6.628
2009	0.597
2010	2.824
2011	5.248
2012	4.576
2013	2.359
2014	1.025
2015	-0.523
2016	-0.532
2017	0.576
2018	0.439
2019	0.565
2020	-0.182
2021	2.305
2022	6.121
2023	4.821
2024	2.979
2025	2.500
2026	1.978
2027	1.984
2028	1.984
2029	1.964