Year	Percent change (Units)
1980	9.300
1981	38.700
1982	1.200
1983	3.600
1984	-10.500
1985	2.100
1986	-4.900
1987	24.400
1988	-17.734
1989	14.400
1990	27.600
1991	14.900
1992	6.100
1993	4.700
1994	15.500
1995	20.270
1996	9.434
1997	0.674
1998	-12.500
1999	-24.103
2000	25.495
2001	-10.439
2002	3.126
2003	4.083
2004	14.818
2005	23.946
2006	-2.312
2007	7.688
2008	17.608
2009	-18.228
2010	17.608
2011	18.258
2012	15.741
2013	1.050
2014	0.286
2015	-7.457
2016	0.955
2017	10.712
2018	14.486
2019	-9.654
2020	-14.856
2021	15.164
2022	8.885
2023	-2.150
2024	16.199
2025	12.806
2026	9.298
2027	7.253
2028	7.423
2029	7.414