Year	Percent change (Units)
1980	-4.718
1981	-23.107
1982	10.619
1983	7.181
1984	0.000
1985	9.896
1986	-15.934
1987	8.459
1988	5.401
1989	-3.277
1990	0.089
1991	-26.094
1992	-28.724
1993	-2.871
1994	12.612
1995	20.078
1996	-2.214
1997	-17.365
1998	4.916
1999	-19.493
2000	-6.078
2001	-34.852
2002	-31.462
2003	8.027
2004	-17.057
2005	9.697
2006	-36.144
2007	102.032
2008	10.737
2009	-15.358
2010	36.976
2011	3.250
2012	-10.781
2013	43.153
2014	11.025
2015	1.447
2016	28.935
2017	-23.297
2018	19.596
2019	2.656
2020	7.245
2021	9.823
2022	26.090
2023	10.392
2024	3.141
2025	4.120
2026	4.632
2027	5.518
2028	1.676
2029	1.759