Year	Percent change (Units)
1980	6.469
1981	-12.305
1982	-2.832
1983	-9.684
1984	-7.057
1985	6.554
1986	-1.172
1987	-3.586
1988	11.299
1989	-1.819
1990	0.619
1991	-21.539
1992	17.164
1993	-1.956
1994	14.313
1995	16.099
1996	-18.262
1997	9.763
1998	-16.739
1999	17.354
2000	15.623
2001	-18.745
2002	20.772
2003	72.658
2004	-1.301
2005	30.407
2006	-7.818
2007	-11.342
2008	11.533
2009	-7.252
2010	9.651
2011	-1.305
2012	-0.288
2013	1.246
2014	-2.240
2015	-7.740
2016	-15.693
2017	29.190
2018	0.866
2019	-3.973
2020	-10.991
2021	-11.938
2022	7.751
2023	8.134
2024	4.362
2025	2.932
2026	2.308
2027	3.583
2028	2.741
2029	3.475