Year	Percent change (Units)
1980	17.710
1981	7.160
1982	2.617
1983	3.114
1984	3.219
1985	-0.721
1986	1.967
1987	5.822
1988	5.518
1989	4.880
1990	7.861
1991	3.206
1992	2.862
1993	-0.545
1994	0.123
1995	-1.265
1996	3.187
1997	-1.124
1998	4.660
1999	1.098
2000	0.432
2001	0.935
2002	2.550
2003	1.809
2004	2.756
2005	2.543
2006	0.009
2007	5.230
2008	0.728
2009	2.399
2010	2.925
2011	4.044
2012	1.839
2013	1.059
2014	1.327
2015	0.900
2016	-1.121
2017	2.356
2018	1.739
2019	0.689
2020	2.778
2021	1.216
2022	9.250
2023	3.282
2024	2.221
2025	1.997
2026	1.997
2027	1.997
2028	1.997
2029	1.997