Year	Percent change (Units)
1981	-6.062
1982	0.041
1983	3.918
1984	5.307
1985	6.459
1986	4.248
1987	3.695
1988	6.340
1989	8.423
1990	5.014
1991	5.407
1992	2.017
1993	0.683
1994	10.602
1995	11.787
1996	5.124
1997	9.912
1998	8.001
1999	8.979
2000	12.662
2001	1.510
2002	-0.455
2003	3.041
2004	8.613
2005	5.828
2006	9.396
2007	5.364
2008	1.401
2009	-10.665
2010	10.284
2011	3.660
2012	2.406
2013	1.304
2014	3.333
2015	7.608
2016	5.426
2017	5.706
2018	3.962
2019	5.194
2020	-2.481
2021	9.453
2022	1.845
2023	-1.292
2024	0.800
2025	3.000
2026	3.700
2027	3.700
2028	3.700
2029	3.700