Year	Percent change (Units)
1980	-1.079
1981	6.122
1982	-1.090
1983	-9.778
1984	13.918
1985	-13.240
1986	-2.466
1987	1.293
1988	22.045
1989	-7.292
1990	-6.385
1991	-5.649
1992	23.959
1993	-0.104
1994	2.045
1995	2.752
1996	-0.052
1997	1.177
1998	4.442
1999	-3.914
2000	6.743
2001	-3.144
2002	1.447
2003	-1.575
2004	-0.609
2005	1.292
2006	5.777
2007	3.055
2008	-2.985
2009	0.537
2010	1.226
2011	3.264
2012	5.804
2013	7.731
2014	1.264
2015	11.265
2016	7.088
2017	3.749
2018	3.479
2019	3.264
2020	-0.562
2021	8.523
2022	3.905
2023	4.154
2024	5.761
2025	4.140
2026	3.272
2027	2.474
2028	2.123
2029	2.113