Year	Percent change (Units)
1986	18.372
1987	9.524
1988	4.712
1989	7.200
1990	4.851
1991	0.979
1992	1.321
1993	1.391
1994	2.800
1995	2.918
1996	2.552
1997	0.830
1998	0.366
1999	0.508
2000	3.976
2001	1.816
2002	2.723
2003	1.554
2004	2.700
2005	3.155
2006	2.635
2007	3.184
2008	3.375
2009	1.959
2010	4.026
2011	1.847
2012	0.950
2013	1.625
2014	0.758
2015	0.084
2016	1.336
2017	1.594
2018	1.889
2019	1.854
2020	1.437
2021	5.949
2022	7.219
2023	4.655
2024	2.422
2025	2.421
2026	2.319
2027	2.014
2028	1.964
2029	2.218