Year	Percent change (Units)
1980	7.661
1981	5.461
1982	-0.324
1983	-9.329
1984	3.801
1985	2.089
1986	12.106
1987	7.738
1988	-9.422
1989	-13.422
1990	-5.090
1991	2.219
1992	-0.541
1993	5.244
1994	12.308
1995	7.411
1996	2.799
1997	6.476
1998	-0.392
1999	1.495
2000	2.695
2001	0.617
2002	5.454
2003	4.165
2004	4.959
2005	6.285
2006	7.529
2007	8.518
2008	9.119
2009	1.096
2010	8.334
2011	6.325
2012	6.142
2013	5.852
2014	2.384
2015	3.252
2016	3.954
2017	2.522
2018	3.970
2019	2.240
2020	-10.869
2021	13.418
2022	2.684
2023	-0.552
2024	2.538
2025	2.680
2026	2.301
2027	2.300
2028	2.300
2029	2.300