Year	Percent change (Units)
1980	27.859
1981	-31.697
1982	-25.374
1983	-3.527
1984	-8.189
1985	-5.414
1986	23.394
1987	23.854
1988	46.446
1989	3.068
1990	-10.865
1991	-6.370
1992	-34.720
1993	0.134
1994	-17.883
1995	8.732
1996	18.539
1997	-0.656
1998	-4.299
1999	-4.970
2000	-7.774
2001	-11.031
2002	-2.979
2003	1.644
2004	34.421
2005	31.007
2006	35.333
2007	67.032
2008	11.693
2009	-20.841
2010	4.978
2011	8.349
2012	-9.499
2013	-7.724
2014	-11.469
2015	-5.143
2016	-10.425
2017	0.294
2018	8.646
2019	4.503
2020	0.693
2021	-14.871
2022	6.311
2023	-1.536
2024	36.879
2025	19.816
2026	-8.704
2027	-6.521
2028	4.711
2029	12.031