Year	Percent change (Units)
1980	12.100
1981	5.800
1982	5.900
1983	-7.400
1984	-2.100
1985	2.800
1986	18.500
1987	27.600
1988	22.400
1989	8.300
1990	15.600
1991	7.200
1992	13.500
1993	-5.800
1994	11.300
1995	9.700
1996	8.400
1997	5.340
1998	21.515
1999	3.123
2000	-7.367
2001	3.637
2002	3.920
2003	11.068
2004	8.877
2005	-4.828
2006	4.011
2007	9.670
2008	2.506
2009	-18.357
2010	-3.854
2011	-4.854
2012	-11.660
2013	7.208
2014	7.979
2015	7.676
2016	4.116
2017	8.281
2018	4.851
2019	4.216
2020	-10.012
2021	11.691
2022	9.770
2023	2.451
2024	3.689
2025	3.086
2026	3.031
2027	2.770
2028	2.651
2029	2.651