Year	Percent change (Units)
1980	-2.649
1981	13.260
1982	4.890
1983	10.857
1984	-4.363
1985	12.902
1986	2.210
1987	-7.533
1988	-5.928
1989	7.562
1990	9.732
1991	0.564
1992	0.215
1993	-4.360
1994	-11.726
1995	15.281
1996	-12.337
1997	-8.966
1998	18.336
1999	-3.954
2000	-11.322
2001	5.451
2002	13.502
2003	22.768
2004	15.919
2005	4.663
2006	0.250
2007	27.826
2008	25.166
2009	-9.150
2010	-6.240
2011	10.469
2012	3.658
2013	5.813
2014	3.694
2015	-2.837
2016	2.033
2017	20.038
2018	12.503
2019	1.973
2020	21.326
2021	15.732
2022	-0.799
2023	4.988
2024	-0.478
2025	7.720
2026	8.321
2027	6.114
2028	7.729
2029	5.828