Year	Percent change (Units)
1980	0.788
1981	-9.800
1982	-1.900
1983	0.900
1984	1.760
1985	1.156
1986	1.960
1987	1.175
1988	3.407
1989	4.075
1990	3.129
1991	-6.306
1992	1.181
1993	2.100
1994	-0.042
1995	1.679
1996	2.154
1997	3.693
1998	3.917
1999	4.699
2000	4.457
2001	5.980
2002	-12.408
2003	9.785
2004	5.257
2005	4.756
2006	5.399
2007	5.711
2008	6.713
2009	-3.979
2010	0.619
2011	1.578
2012	3.011
2013	2.300
2014	3.339
2015	3.132
2016	3.993
2017	3.933
2018	3.194
2019	4.411
2020	-7.138
2021	5.740
2022	4.000
2023	3.800
2024	4.500
2025	4.600
2026	4.700
2027	4.600
2028	4.500
2029	4.500