Year	Percent change (Units)
1980	13.400
1981	3.447
1982	10.811
1983	-21.696
1984	-14.864
1985	-14.900
1986	34.103
1987	6.637
1988	10.149
1989	3.761
1990	3.630
1991	3.009
1992	-3.366
1993	14.223
1994	8.014
1995	-27.850
1996	8.591
1997	1.325
1998	40.396
1999	17.640
2000	-8.856
2001	9.313
2002	28.998
2003	1.539
2004	-3.671
2005	10.320
2006	10.187
2007	-1.392
2008	6.776
2009	8.859
2010	-4.042
2011	43.628
2012	63.415
2013	8.164
2014	-1.698
2015	0.015
2016	-21.223
2017	0.031
2018	20.834
2019	-8.568
2020	-4.795
2021	-1.671
2022	33.913
2023	-25.023
2024	50.380
2025	12.307
2026	5.215
2027	-3.792
2028	-8.228
2029	-11.143