Year	Percent change (Units)
1980	13.200
1981	12.700
1982	1.800
1983	-17.400
1984	-2.400
1985	-3.500
1986	-5.800
1987	7.700
1988	10.700
1989	16.900
1990	8.600
1991	-11.195
1992	19.880
1993	-5.076
1994	7.194
1995	33.938
1996	19.538
1997	-10.999
1998	-14.458
1999	-18.517
2000	27.453
2001	25.644
2002	29.672
2003	17.975
2004	17.758
2005	9.512
2006	-2.083
2007	-0.413
2008	-1.837
2009	-2.104
2010	7.539
2011	6.637
2012	2.939
2013	1.740
2014	6.935
2015	13.718
2016	-3.371
2017	-10.430
2018	14.110
2019	12.813
2020	2.220
2021	1.842
2022	4.047
2023	5.531
2024	5.444
2025	7.313
2026	8.326
2027	9.102
2028	9.585
2029	4.673