Year	Percent change (Units)
1980	188.570
1981	101.494
1982	131.504
1983	190.692
1984	444.878
1985	185.175
1986	19.653
1987	16.125
1988	16.397
1989	20.692
1990	17.612
1991	18.037
1992	9.370
1993	11.248
1994	14.452
1995	8.104
1996	10.587
1997	6.988
1998	8.622
1999	1.344
2000	0.000
2001	1.409
2002	6.496
2003	-1.886
2004	1.207
2005	2.386
2006	-0.097
2007	3.397
2008	3.805
2009	3.915
2010	2.662
2011	2.170
2012	1.635
2013	1.816
2014	-0.196
2015	-0.997
2016	-0.202
2017	0.400
2018	0.797
2019	0.601
2020	-0.694
2021	2.805
2022	5.263
2023	2.958
2024	2.623
2025	2.319
2026	2.095
2027	2.090
2028	1.998
2029	1.998