Year	Percent change (Units)
1980	-7.000
1981	-5.500
1982	-3.500
1983	-3.400
1984	9.172
1985	27.621
1986	20.012
1987	-0.598
1988	20.953
1989	-9.493
1990	-7.350
1991	22.628
1992	4.967
1993	12.273
1994	7.099
1995	4.234
1996	13.201
1997	0.883
1998	36.583
1999	9.619
2000	-7.627
2001	11.264
2002	-4.341
2003	9.448
2004	21.180
2005	15.743
2006	26.344
2007	21.660
2008	24.748
2009	-20.991
2010	35.046
2011	49.337
2012	10.706
2013	-1.135
2014	-16.545
2015	-8.545
2016	-3.653
2017	-2.540
2018	4.230
2019	2.127
2020	-1.232
2021	9.619
2022	4.080
2023	-4.647
2024	9.013
2025	5.902
2026	7.753
2027	5.705
2028	5.739
2029	7.583