Year	Percent change (Units)
1980	7.494
1981	2.777
1982	6.406
1983	6.994
1984	4.186
1985	-0.930
1986	0.484
1987	-1.222
1988	5.952
1989	1.013
1990	3.503
1991	2.286
1992	7.123
1993	7.604
1994	3.212
1995	1.923
1996	3.250
1997	2.348
1998	4.849
1999	5.972
2000	7.018
2001	2.491
2002	3.349
2003	6.296
2004	6.981
2005	6.769
2006	6.467
2007	8.294
2008	6.242
2009	2.541
2010	4.337
2011	1.984
2012	3.728
2013	5.416
2014	4.351
2015	2.485
2016	3.558
2017	4.292
2018	2.110
2019	2.167
2020	-4.645
2021	2.591
2022	4.891
2023	2.617
2024	3.567
2025	3.162
2026	2.665
2027	2.718
2028	2.715
2029	2.812