Year	Percent change (Units)
1980	7.051
1981	11.224
1982	6.839
1983	4.996
1984	3.383
1985	4.153
1986	0.794
1987	2.021
1988	5.321
1989	0.000
1990	2.047
1991	2.253
1992	2.397
1993	1.473
1994	2.569
1995	2.890
1996	6.425
1997	1.026
1998	-0.847
1999	-1.207
2000	0.614
2001	1.149
2002	2.195
2003	2.621
2004	3.067
2005	3.651
2006	4.240
2007	2.318
2008	6.394
2009	-1.104
2010	0.918
2011	1.656
2012	1.247
2013	0.510
2014	1.201
2015	-0.862
2016	0.661
2017	1.150
2018	0.270
2019	0.186
2020	0.122
2021	3.239
2022	6.274
2023	4.390
2024	3.063
2025	2.254
2026	1.258
2027	1.258
2028	1.258
2029	1.258