Year	Percent change (Units)
1980	11.602
1981	12.000
1982	9.300
1983	8.400
1984	7.000
1985	5.820
1986	2.900
1987	4.082
1988	5.135
1989	6.572
1990	4.957
1991	4.545
1992	3.254
1993	3.326
1994	1.614
1995	0.398
1996	1.063
1997	1.217
1998	1.349
1999	1.310
2000	2.952
2001	2.665
2002	2.007
2003	1.290
2004	0.147
2005	0.774
2006	1.275
2007	1.583
2008	3.916
2009	1.634
2010	1.686
2011	3.324
2012	3.162
2013	2.216
2014	1.209
2015	-0.156
2016	0.389
2017	0.839
2018	1.169
2019	1.137
2020	0.383
2021	2.066
2022	7.172
2023	4.340
2024	1.212
2025	1.934
2026	2.000
2027	2.000
2028	2.000
2029	2.000