Year	Percent change (Units)
1980	-4.014
1981	-3.577
1982	32.512
1983	-7.350
1984	9.079
1985	-21.300
1986	6.471
1987	-14.224
1988	0.499
1989	-11.097
1990	17.633
1991	5.473
1992	-13.182
1993	-17.657
1994	20.971
1995	-0.079
1996	-41.792
1997	-22.457
1998	55.236
1999	-1.414
2000	1.723
2001	8.766
2002	11.102
2003	22.639
2004	1.893
2005	56.443
2006	17.182
2007	69.992
2008	-31.955
2009	3.528
2010	86.968
2011	-19.509
2012	10.992
2013	-0.547
2014	-13.909
2015	-28.373
2016	7.422
2017	14.988
2018	17.291
2019	44.459
2020	-16.056
2021	4.455
2022	10.379
2023	14.205
2024	3.071
2025	0.285
2026	8.808
2027	3.450
2028	1.945
2029	4.808