Year	Percent change (Units)
1980	2.800
1981	3.000
1982	2.218
1983	6.329
1984	7.389
1985	7.534
1986	0.328
1987	-2.527
1988	35.862
1989	-1.035
1990	6.468
1991	10.747
1992	4.204
1993	5.565
1994	10.028
1995	4.400
1996	4.403
1997	3.011
1998	2.101
1999	8.353
2000	7.650
2001	3.314
2002	6.932
2003	2.349
2004	5.073
2005	-0.494
2006	1.817
2007	4.838
2008	-1.239
2009	2.116
2010	3.291
2011	2.577
2012	1.865
2013	0.863
2014	3.422
2015	8.092
2016	2.728
2017	2.582
2018	3.047
2019	2.556
2020	-13.469
2021	-2.458
2022	0.164
2023	9.596
2024	6.426
2025	5.157
2026	5.116
2027	4.781
2028	4.896
2029	4.899