Year	Percent change (Units)
1980	10.778
1981	1.213
1982	-7.662
1983	-2.589
1984	8.150
1985	3.348
1986	7.672
1987	10.929
1988	16.212
1989	11.570
1990	8.827
1991	6.614
1992	6.923
1993	3.271
1994	8.836
1995	10.277
1996	8.174
1997	11.908
1998	2.338
1999	4.980
2000	8.312
2001	-5.580
2002	-1.954
2003	2.105
2004	9.644
2005	6.945
2006	9.478
2007	8.762
2008	5.789
2009	-8.311
2010	12.647
2011	7.178
2012	4.019
2013	3.010
2014	3.902
2015	0.320
2016	0.474
2017	4.115
2018	2.854
2019	0.511
2020	-13.129
2021	6.343
2022	6.960
2023	2.710
2024	1.541
2025	2.487
2026	2.818
2027	2.948
2028	2.913
2029	2.813