Year	Percent change (Units)
1980	6.325
1981	6.807
1982	5.440
1983	3.335
1984	5.665
1985	3.190
1986	1.737
1987	1.408
1988	1.868
1989	2.249
1990	2.777
1991	3.116
1992	3.426
1993	3.234
1994	2.711
1995	1.611
1996	1.771
1997	1.167
1998	0.817
1999	0.516
2000	1.956
2001	2.302
2002	1.681
2003	1.302
2004	1.964
2005	2.102
2006	1.686
2007	2.200
2008	3.230
2009	0.406
2010	1.691
2011	3.542
2012	2.569
2013	2.118
2014	1.465
2015	0.810
2016	0.972
2017	2.228
2018	2.122
2019	1.495
2020	1.391
2021	2.756
2022	8.614
2023	7.710
2024	3.920
2025	2.783
2026	2.309
2027	2.041
2028	2.059
2029	2.059