Year	Percent change (Units)
1980	-6.431
1981	18.375
1982	7.000
1983	-28.935
1984	-46.670
1985	-36.696
1986	3.164
1987	8.613
1988	13.616
1989	-10.425
1990	-4.478
1991	3.084
1992	2.992
1993	32.982
1994	42.292
1995	14.078
1996	0.683
1997	5.324
1998	14.189
1999	-0.635
2000	-1.214
2001	17.908
2002	12.972
2003	11.546
2004	-0.620
2005	5.056
2006	11.295
2007	17.732
2008	5.463
2009	-14.549
2010	-12.803
2011	4.204
2012	3.077
2013	11.429
2014	11.182
2015	16.572
2016	3.666
2017	13.995
2018	2.161
2019	10.069
2020	-12.539
2021	-19.240
2022	31.405
2023	15.607
2024	10.975
2025	10.847
2026	9.509
2027	8.132
2028	6.797
2029	6.408