Year	Percent change (Units)
1980	60.895
1981	8.862
1982	5.007
1983	-1.445
1984	0.265
1985	19.645
1986	-13.747
1987	7.394
1988	-7.583
1989	11.009
1990	8.842
1991	-19.530
1992	-3.655
1993	-4.357
1994	45.793
1995	-2.060
1996	-17.876
1997	17.398
1998	6.345
1999	-1.907
2000	-7.315
2001	-1.754
2002	-8.227
2003	-23.188
2004	10.552
2005	6.962
2006	2.551
2007	7.546
2008	-0.910
2009	12.257
2010	12.262
2011	-19.480
2012	8.218
2013	-36.779
2014	141.253
2015	34.100
2016	14.463
2017	-1.767
2018	-1.597
2019	9.368
2020	7.355
2021	-11.516
2022	-5.466
2023	5.547
2024	7.291
2025	9.930
2026	5.506
2027	8.904
2028	6.553
2029	6.739