Year	Percent change (Units)
1980	-5.864
1981	7.365
1982	7.181
1983	5.995
1984	38.636
1985	30.853
1986	4.399
1987	22.672
1988	55.798
1989	34.594
1990	79.919
1991	7.902
1992	5.165
1993	2.788
1994	14.314
1995	9.216
1996	3.949
1997	8.366
1998	7.820
1999	5.101
2000	9.019
2001	4.384
2002	10.512
2003	42.655
2004	28.740
2005	7.437
2006	5.000
2007	8.878
2008	4.517
2009	5.765
2010	6.238
2011	7.760
2012	3.907
2013	3.876
2014	1.582
2015	2.344
2016	1.695
2017	4.204
2018	1.171
2019	3.656
2020	5.554
2021	8.496
2022	7.827
2023	3.569
2024	3.973
2025	3.973
2026	3.973
2027	3.973
2028	3.973
2029	3.973