Year	Percent change (Units)
1980	-0.779
1981	4.365
1982	3.429
1983	4.758
1984	6.823
1985	4.258
1986	6.941
1987	10.027
1988	2.121
1989	0.253
1990	9.255
1991	0.926
1992	5.984
1993	8.042
1994	-5.456
1995	7.190
1996	7.007
1997	7.528
1998	3.092
1999	-3.263
2000	6.933
2001	-5.750
2002	6.448
2003	5.763
2004	9.796
2005	8.992
2006	6.948
2007	5.044
2008	0.815
2009	-4.823
2010	8.427
2011	11.200
2012	4.788
2013	8.486
2014	4.940
2015	6.084
2016	3.323
2017	7.502
2018	3.013
2019	0.819
2020	1.860
2021	11.439
2022	5.533
2023	4.517
2024	3.102
2025	3.187
2026	3.282
2027	3.445
2028	3.454
2029	3.485