Year	Percent change (Units)
1980	-6.343
1981	6.202
1982	-4.486
1983	-33.245
1984	11.225
1985	5.889
1986	-9.235
1987	20.703
1988	-27.399
1989	5.141
1990	-1.442
1991	28.659
1992	-7.932
1993	20.722
1994	29.253
1995	16.223
1996	5.454
1997	-13.509
1998	-8.869
1999	-13.172
2000	19.133
2001	21.488
2002	-2.691
2003	-3.714
2004	8.988
2005	14.180
2006	7.035
2007	5.990
2008	12.717
2009	-5.832
2010	12.364
2011	2.432
2012	0.207
2013	8.350
2014	5.306
2015	-4.074
2016	-15.272
2017	19.130
2018	3.533
2019	-0.094
2020	-14.890
2021	16.180
2022	7.104
2023	3.099
2024	-0.374
2025	0.642
2026	1.401
2027	1.714
2028	2.088
2029	2.199