Year	Percent change (Units)
1980	13.342
1981	29.560
1982	28.946
1983	2.209
1984	32.654
1985	-7.034
1986	4.218
1987	-1.831
1988	12.375
1989	0.866
1990	17.419
1991	-5.248
1992	-1.049
1993	-7.682
1994	14.737
1995	11.782
1996	0.173
1997	23.850
1998	-16.340
1999	29.913
2000	0.855
2001	-5.406
2002	5.457
2003	-7.095
2004	7.731
2005	18.927
2006	-0.345
2007	8.796
2008	-11.785
2009	-32.029
2010	18.201
2011	-0.811
2012	16.785
2013	39.668
2014	1.154
2015	-7.360
2016	-8.368
2017	-5.457
2018	11.882
2019	-8.818
2020	-18.569
2021	31.686
2022	-5.606
2023	-23.048
2024	12.650
2025	27.696
2026	1.256
2027	3.812
2028	2.776
2029	3.905