Year	Percent change (Units)
1980	-23.031
1981	-22.434
1982	-15.942
1983	-0.225
1984	-17.055
1985	25.362
1986	-26.517
1987	0.885
1988	25.828
1989	23.083
1990	3.272
1991	9.313
1992	14.463
1993	-15.272
1994	25.657
1995	-13.165
1996	35.251
1997	23.470
1998	-20.721
1999	15.347
2000	-21.308
2001	-6.363
2002	12.959
2003	6.550
2004	8.437
2005	3.538
2006	4.006
2007	-7.423
2008	32.451
2009	-24.925
2010	46.388
2011	-14.499
2012	-10.689
2013	-0.726
2014	10.504
2015	12.877
2016	3.969
2017	5.684
2018	-15.343
2019	14.342
2020	7.359
2021	-14.696
2022	-57.194
2023	75.974
2024	1.123
2025	15.454
2026	5.154
2027	5.997
2028	2.448
2029	2.538