Year	Percent change (Units)
1980	7.357
1981	13.899
1982	-1.491
1983	-1.951
1984	14.770
1985	8.087
1986	1.115
1987	-2.065
1988	7.153
1989	5.854
1990	1.478
1991	-1.315
1992	3.681
1993	-0.475
1994	1.360
1995	2.743
1996	2.948
1997	14.774
1998	2.557
1999	3.176
2000	12.481
2001	0.135
2002	-1.801
2003	-1.128
2004	9.393
2005	6.716
2006	6.723
2007	11.165
2008	3.968
2009	-8.541
2010	12.207
2011	3.995
2012	1.036
2013	13.772
2014	-4.828
2015	3.842
2016	6.029
2017	-0.141
2018	3.362
2019	-0.661
2020	-5.662
2021	13.545
2022	6.293
2023	2.655
2024	3.220
2025	3.252
2026	4.206
2027	3.380
2028	4.203
2029	3.423