Year	Percent change (Units)
1980	14.044
1981	9.546
1982	7.737
1983	3.657
1984	-0.797
1985	10.574
1986	4.242
1987	-1.243
1988	11.281
1989	1.575
1990	6.848
1991	-20.848
1992	31.952
1993	1.009
1994	29.837
1995	14.162
1996	11.217
1997	13.024
1998	0.296
1999	6.739
2000	-2.196
2001	1.528
2002	9.916
2003	10.953
2004	28.658
2005	13.655
2006	6.211
2007	25.413
2008	18.315
2009	4.722
2010	10.472
2011	16.396
2012	1.577
2013	-3.218
2014	7.399
2015	0.692
2016	2.241
2017	11.042
2018	3.551
2019	-5.183
2020	-15.042
2021	19.584
2022	7.331
2023	1.200
2024	4.800
2025	6.600
2026	6.600
2027	6.600
2028	6.600
2029	6.600