Year	Percent change (Units)
1980	-8.903
1981	4.450
1982	2.765
1983	0.385
1984	-1.343
1985	0.668
1986	13.466
1987	8.782
1988	5.019
1989	-1.923
1990	-5.619
1991	15.311
1992	26.721
1993	54.768
1994	-4.184
1995	-8.133
1996	-5.330
1997	-21.670
1998	10.215
1999	12.251
2000	-4.630
2001	-5.292
2002	-17.404
2003	14.943
2004	-6.757
2005	12.361
2006	-7.404
2007	1.928
2008	2.757
2009	-12.875
2010	3.744
2011	-2.212
2012	-3.461
2013	1.986
2014	109.043
2015	36.353
2016	-3.496
2017	22.749
2018	-7.619
2019	9.669
2020	0.053
2021	11.675
2022	-10.408
2023	8.875
2024	4.274
2025	4.067
2026	3.766
2027	3.314
2028	3.269
2029	3.415