Year	Percent change (Units)
1980	1.137
1981	14.701
1982	-7.955
1983	3.060
1984	2.970
1985	-0.299
1986	11.437
1987	8.832
1988	8.644
1989	18.843
1990	4.489
1991	4.416
1992	-1.643
1993	4.004
1994	18.287
1995	2.991
1996	-2.406
1997	10.088
1998	6.339
1999	6.701
2000	7.313
2001	15.678
2002	1.907
2003	7.213
2004	15.231
2005	1.491
2006	6.345
2007	17.699
2008	-2.585
2009	-2.161
2010	6.507
2011	-3.939
2012	1.634
2013	-0.732
2014	-2.936
2015	-2.818
2016	2.021
2017	3.209
2018	3.473
2019	-5.056
2020	-10.958
2021	12.380
2022	13.896
2023	9.230
2024	0.523
2025	1.417
2026	1.783
2027	1.783
2028	1.621
2029	1.300