Year	Percent change (Units)
1981	7.780
1982	5.714
1983	8.393
1984	4.068
1985	4.414
1986	8.333
1987	7.469
1988	4.149
1989	0.100
1990	0.100
1991	1.690
1992	3.568
1993	2.520
1994	32.200
1995	7.700
1996	3.500
1997	5.203
1998	1.989
1999	1.555
2000	3.606
2001	4.783
2002	4.399
2003	-0.109
2004	4.443
2005	2.531
2006	2.037
2007	1.456
2008	2.509
2009	-0.123
2010	5.101
2011	1.967
2012	3.409
2013	0.415
2014	0.925
2015	0.963
2016	0.680
2017	0.753
2018	0.602
2019	1.566
2020	2.312
2021	5.579
2022	5.080
2023	4.005
2024	3.000
2025	2.500
2026	1.800
2027	2.000
2028	2.000
2029	2.000