Year	Percent change (Units)
1980	10.909
1981	7.650
1982	7.614
1983	4.953
1984	4.045
1985	2.808
1986	0.000
1987	-0.210
1988	6.705
1989	25.668
1990	16.192
1991	8.155
1992	4.017
1993	3.304
1994	3.524
1995	2.353
1996	6.501
1997	3.038
1998	3.079
1999	0.598
2000	0.674
2001	1.768
2002	1.835
2003	1.627
2004	3.365
2005	3.491
2006	6.255
2007	4.278
2008	12.712
2009	-1.286
2010	4.931
2011	4.179
2012	4.609
2013	4.898
2014	2.989
2015	-1.098
2016	-0.624
2017	3.614
2018	4.451
2019	0.677
2020	0.397
2021	1.319
2022	4.224
2023	2.163
2024	2.720
2025	2.437
2026	2.477
2027	2.471
2028	2.466
2029	2.466