Year	Percent change (Units)
1980	-11.300
1981	8.064
1982	-7.251
1983	-37.559
1984	-27.838
1985	-1.949
1986	-4.522
1987	7.641
1988	-11.966
1989	13.227
1990	25.303
1991	38.888
1992	0.474
1993	4.438
1994	3.829
1995	3.194
1996	22.602
1997	1.456
1998	12.429
1999	17.799
2000	10.091
2001	47.514
2002	23.426
2003	8.968
2004	14.866
2005	11.913
2006	12.362
2007	-6.763
2008	15.200
2009	0.663
2010	-18.579
2011	25.987
2012	40.277
2013	9.067
2014	-2.671
2015	-0.940
2016	-6.054
2017	34.794
2018	5.094
2019	-4.007
2020	-17.783
2021	19.481
2022	30.281
2023	-2.577
2024	1.532
2025	3.043
2026	1.363
2027	29.864
2028	19.422
2029	9.139