Year	Percent change (Units)
1980	-6.954
1981	-17.403
1982	13.836
1983	-26.708
1984	-6.224
1985	18.875
1986	31.048
1987	-9.655
1988	9.013
1989	-8.201
1990	18.165
1991	-2.844
1992	-5.971
1993	-27.316
1994	-6.091
1995	26.336
1996	8.538
1997	-1.342
1998	12.318
1999	-11.253
2000	-6.925
2001	11.279
2002	11.675
2003	22.115
2004	1.526
2005	-2.569
2006	-3.220
2007	4.135
2008	4.873
2009	11.412
2010	-2.250
2011	26.140
2012	-7.175
2013	21.000
2014	5.831
2015	11.365
2016	-2.501
2017	4.670
2018	4.528
2019	2.797
2020	10.404
2021	4.734
2022	9.275
2023	6.694
2024	5.757
2025	5.212
2026	7.305
2027	7.275
2028	7.253
2029	4.898