Year	Percent change (Units)
1980	-3.447
1981	4.284
1982	-3.257
1983	33.254
1984	0.976
1985	11.414
1986	-12.517
1987	-6.216
1988	30.154
1989	6.340
1990	4.201
1991	-6.745
1992	10.693
1993	41.795
1994	-13.193
1995	5.276
1996	18.556
1997	22.201
1998	30.405
1999	-2.723
2000	-23.740
2001	45.446
2002	-11.769
2003	-9.991
2004	8.088
2005	24.966
2006	1.304
2007	-10.540
2008	3.335
2009	-0.409
2010	-10.294
2011	4.209
2012	9.079
2013	3.884
2014	9.682
2015	4.072
2016	9.530
2017	9.141
2018	-3.441
2019	-4.252
2020	-18.556
2021	-1.903
2022	9.475
2023	15.259
2024	3.469
2025	7.202
2026	4.374
2027	3.342
2028	2.171
2029	2.103