Year	Percent change (Units)
1980	-5.996
1981	-21.497
1982	1.437
1983	39.276
1984	-25.398
1985	1.736
1986	-2.625
1987	244.205
1988	110.298
1989	9.831
1990	0.207
1991	-3.747
1992	-7.582
1993	20.746
1994	6.386
1995	0.376
1996	85.378
1997	26.918
1998	19.802
1999	10.790
2000	13.149
2001	32.828
2002	6.938
2003	13.626
2004	-9.872
2005	-6.789
2006	-1.879
2007	-3.381
2008	-4.747
2009	10.403
2010	-26.590
2011	10.296
2012	33.308
2013	-9.540
2014	-11.856
2015	14.848
2016	-11.195
2017	6.928
2018	-2.942
2019	-7.705
2020	18.195
2021	-15.594
2022	-13.612
2023	-3.499
2024	1.142
2025	22.754
2026	3.583
2027	2.638
2028	2.606
2029	4.966