Year	Percent change (Units)
1980	1.814
1981	-11.768
1982	0.894
1983	-7.751
1984	-4.334
1985	10.743
1986	0.505
1987	-9.208
1988	10.322
1989	4.184
1990	0.735
1991	-23.013
1992	16.950
1993	-9.543
1994	5.937
1995	15.802
1996	-18.965
1997	12.734
1998	-15.207
1999	14.934
2000	15.931
2001	-13.140
2002	28.422
2003	73.672
2004	-10.214
2005	31.765
2006	-10.348
2007	-10.222
2008	13.783
2009	-10.449
2010	18.367
2011	2.361
2012	0.870
2013	0.514
2014	-4.302
2015	-8.755
2016	-16.361
2017	33.442
2018	0.595
2019	-3.187
2020	-8.424
2021	-11.917
2022	6.264
2023	7.172
2024	1.839
2025	1.298
2026	1.178
2027	2.337
2028	1.311
2029	1.368