Year	Percent change (Units)
1980	7.828
1981	0.703
1982	7.209
1983	12.148
1984	18.375
1985	6.536
1986	3.681
1987	14.497
1988	7.106
1989	11.218
1990	8.460
1991	5.600
1992	14.678
1993	10.157
1994	14.843
1995	20.104
1996	9.891
1997	14.936
1998	-9.221
1999	13.854
2000	17.375
2001	11.763
2002	7.342
2003	-6.966
2004	6.996
2005	3.922
2006	2.774
2007	8.777
2008	-5.920
2009	6.308
2010	2.482
2011	-0.636
2012	-2.196
2013	-0.350
2014	16.305
2015	59.149
2016	0.764
2017	3.916
2018	8.582
2019	7.179
2020	15.504
2021	18.425
2022	22.454
2023	-12.166
2024	2.000
2025	3.000
2026	3.000
2027	3.000
2028	3.000
2029	6.000