Year	Percent change (Units)
1980	7.135
1981	8.467
1982	5.511
1983	3.117
1984	1.716
1985	1.044
1986	1.431
1987	0.392
1988	3.513
1989	2.112
1990	7.007
1991	4.401
1992	4.797
1993	3.467
1994	3.485
1995	3.238
1996	3.262
1997	2.916
1998	5.313
1999	2.466
2000	1.204
2001	1.189
2002	1.603
2003	1.157
2004	2.183
2005	3.211
2006	3.146
2007	2.288
2008	4.473
2009	1.019
2010	2.119
2011	2.964
2012	1.248
2013	3.223
2014	2.663
2015	2.683
2016	1.742
2017	3.510
2018	0.165
2019	0.991
2020	-1.390
2021	3.234
2022	3.775
2023	2.489
2024	2.793
2025	2.514
2026	2.172
2027	2.048
2028	2.039
2029	2.059