Year	Percent change (Units)
1980	6.661
1981	6.407
1982	4.726
1983	3.785
1984	5.049
1985	2.804
1986	1.104
1987	1.642
1988	1.866
1989	2.479
1990	3.130
1991	2.730
1992	3.741
1993	3.096
1994	2.388
1995	0.555
1996	2.336
1997	0.996
1998	0.493
1999	1.663
2000	1.824
2001	1.765
2002	1.682
2003	1.336
2004	2.512
2005	1.531
2006	1.629
2007	3.467
2008	1.469
2009	1.052
2010	2.182
2011	3.395
2012	2.913
2013	1.987
2014	0.807
2015	1.071
2016	1.585
2017	2.331
2018	1.715
2019	1.827
2020	1.012
2021	3.789
2022	10.540
2023	5.653
2024	3.249
2025	2.419
2026	2.039
2027	2.059
2028	2.059
2029	2.059