Year	Percent change (Units)
1980	-7.161
1981	0.139
1982	29.925
1983	7.209
1984	3.210
1985	-5.100
1986	6.471
1987	-14.224
1988	0.499
1989	-11.097
1990	17.633
1991	-29.868
1992	-1.312
1993	-11.584
1994	20.846
1995	1.605
1996	-39.120
1997	-18.903
1998	45.510
1999	-4.627
2000	4.135
2001	5.949
2002	13.796
2003	20.886
2004	24.094
2005	57.960
2006	13.298
2007	42.299
2008	-17.997
2009	-7.423
2010	66.795
2011	-17.772
2012	8.204
2013	2.446
2014	-5.490
2015	-29.360
2016	10.288
2017	10.920
2018	14.698
2019	45.588
2020	-17.818
2021	5.870
2022	8.322
2023	14.404
2024	8.864
2025	0.848
2026	7.851
2027	7.669
2028	4.980
2029	5.266