Year	Percent change (Units)
1980	-1.524
1981	17.123
1982	-2.471
1983	1.360
1984	-5.454
1985	-7.965
1986	9.285
1987	7.523
1988	-7.921
1989	-39.867
1990	13.900
1991	-5.900
1992	29.900
1993	6.100
1994	-2.629
1995	-3.100
1996	7.740
1997	-2.331
1998	-5.459
1999	-1.184
2000	20.812
2001	1.814
2002	4.244
2003	1.242
2004	20.331
2005	16.340
2006	3.223
2007	6.673
2008	5.451
2009	-4.703
2010	-4.001
2011	-2.730
2012	5.717
2013	3.079
2014	0.230
2015	-2.623
2016	-3.506
2017	6.301
2018	-1.357
2019	2.100
2020	-16.752
2021	19.302
2022	7.260
2023	3.449
2024	1.802
2025	2.707
2026	3.005
2027	3.210
2028	3.204
2029	3.192