Year	Percent change (Units)
1980	-13.199
1981	28.437
1982	-10.689
1983	6.322
1984	19.811
1985	3.773
1986	-30.797
1987	21.713
1988	75.479
1989	-0.171
1990	-66.872
1991	-24.522
1992	9.200
1993	18.400
1994	-16.900
1995	13.300
1996	-8.900
1997	5.300
1998	16.100
1999	7.700
2000	11.749
2001	15.488
2002	13.288
2003	17.364
2004	27.755
2005	19.756
2006	16.803
2007	26.048
2008	4.338
2009	-23.233
2010	9.535
2011	11.947
2012	4.585
2013	4.994
2014	1.526
2015	6.064
2016	4.416
2017	7.010
2018	7.452
2019	5.344
2020	-2.934
2021	9.859
2022	13.465
2023	0.356
2024	2.781
2025	2.808
2026	3.314
2027	3.032
2028	3.099
2029	2.856