Year	Percent change (Units)
1980	18.498
1981	14.589
1982	10.287
1983	5.275
1984	4.648
1985	4.858
1986	0.199
1987	3.567
1988	4.719
1989	6.334
1990	3.036
1991	6.300
1992	5.996
1993	1.184
1994	0.700
1995	2.838
1996	2.386
1997	7.711
1998	-1.269
1999	1.560
2000	0.870
2001	4.203
2002	0.319
2003	1.208
2004	0.843
2005	4.671
2006	7.452
2007	4.850
2008	6.462
2009	5.648
2010	5.178
2011	7.583
2012	7.091
2013	2.178
2014	1.626
2015	0.254
2016	-0.283
2017	3.536
2018	5.168
2019	1.572
2020	0.514
2021	1.485
2022	4.998
2023	5.039
2024	3.857
2025	2.832
2026	2.443
2027	2.427
2028	2.427
2029	2.427