Year	Percent change (Units)
1980	2.699
1981	3.164
1982	-8.943
1983	11.003
1984	2.406
1985	11.050
1986	5.947
1987	3.266
1988	-3.605
1989	2.943
1990	-0.026
1991	-5.910
1992	-1.982
1993	6.513
1994	9.278
1995	-2.289
1996	8.090
1997	4.786
1998	1.424
1999	3.116
2000	3.862
2001	6.746
2002	3.557
2003	0.743
2004	8.164
2005	7.117
2006	-4.710
2007	23.370
2008	3.464
2009	8.317
2010	0.954
2011	3.396
2012	3.598
2013	6.805
2014	3.889
2015	8.948
2016	10.951
2017	5.080
2018	0.422
2019	-5.349
2020	-30.688
2021	14.603
2022	22.254
2023	4.812
2024	3.165
2025	3.066
2026	3.273
2027	3.175
2028	3.175
2029	3.175