Year	Percent change (Units)
1980	15.800
1981	14.000
1982	12.800
1983	5.800
1984	44.100
1985	5.600
1986	8.800
1987	1.700
1988	-3.500
1989	1.100
1990	4.700
1991	5.900
1992	-3.800
1993	-0.100
1994	1.979
1995	7.930
1996	0.090
1997	-0.636
1998	2.306
1999	2.296
2000	3.766
2001	1.460
2002	4.495
2003	0.056
2004	-1.885
2005	-0.416
2006	-2.194
2007	-2.500
2008	4.750
2009	-5.199
2010	0.803
2011	6.818
2012	0.823
2013	0.312
2014	2.019
2015	1.172
2016	6.571
2017	3.322
2018	0.241
2019	0.706
2020	0.489
2021	-2.667
2022	-1.962
2023	2.558
2024	2.524
2025	2.384
2026	1.449
2027	1.232
2028	1.200
2029	1.200