Year	Percent change (Units)
1980	-12.265
1981	18.371
1982	6.533
1983	-1.461
1984	62.700
1985	18.317
1986	-4.589
1987	0.521
1988	13.555
1989	-15.107
1990	18.978
1991	10.707
1992	14.516
1993	-9.994
1994	-12.083
1995	5.870
1996	-3.290
1997	4.992
1998	-1.485
1999	-3.666
2000	1.714
2001	9.610
2002	11.391
2003	10.993
2004	7.542
2005	6.128
2006	4.004
2007	0.500
2008	16.717
2009	11.619
2010	0.467
2011	-1.580
2012	4.823
2013	7.705
2014	1.848
2015	-7.085
2016	12.623
2017	1.314
2018	9.109
2019	-2.213
2020	7.904
2021	-5.837
2022	-4.006
2023	0.359
2024	4.001
2025	4.225
2026	0.968
2027	2.791
2028	2.796
2029	3.594