Year	Percent change (Units)
1980	20.000
1981	19.300
1982	-16.400
1983	-10.700
1984	-3.200
1985	-5.900
1986	-2.700
1987	6.900
1988	-6.200
1989	-4.400
1990	-5.800
1991	-5.200
1992	9.700
1993	-7.488
1994	-6.495
1995	15.600
1996	28.417
1997	-5.436
1998	15.017
1999	-12.349
2000	11.595
2001	-4.326
2002	-5.810
2003	2.533
2004	0.332
2005	11.208
2006	5.688
2007	9.770
2008	7.711
2009	24.311
2010	19.455
2011	3.260
2012	8.749
2013	12.202
2014	-7.396
2015	-10.549
2016	-5.737
2017	12.241
2018	-5.790
2019	-2.798
2020	-0.656
2021	-8.332
2022	-12.602
2023	-5.826
2024	139.996
2025	26.901
2026	7.110
2027	0.391
2028	9.419
2029	7.988