Year	Percent change (Units)
1980	-10.962
1981	21.239
1982	5.199
1983	-9.443
1984	20.440
1985	4.346
1986	-10.577
1987	-3.891
1988	3.283
1989	12.711
1990	16.126
1991	2.394
1992	9.326
1993	0.075
1994	0.216
1995	8.489
1996	-4.837
1997	2.296
1998	17.351
1999	5.030
2000	6.771
2001	11.010
2002	18.062
2003	4.624
2004	6.782
2005	11.689
2006	6.436
2007	17.006
2008	12.512
2009	0.830
2010	0.051
2011	8.823
2012	0.614
2013	-7.349
2014	3.219
2015	-1.120
2016	15.822
2017	6.207
2018	4.331
2019	0.953
2020	-11.373
2021	11.357
2022	-0.044
2023	-1.807
2024	3.884
2025	3.778
2026	2.730
2027	3.234
2028	2.563
2029	2.665