Year	Percent change (Units)
1980	9.105
1981	-3.171
1982	8.549
1983	-11.945
1984	10.614
1985	9.861
1986	24.967
1987	12.583
1988	-0.074
1989	10.826
1990	17.991
1991	9.983
1992	4.483
1993	6.460
1994	15.551
1995	-5.448
1996	-1.091
1997	5.596
1998	6.698
1999	1.172
2000	-0.484
2001	2.811
2002	-2.377
2003	7.360
2004	9.809
2005	5.714
2006	9.518
2007	6.221
2008	2.037
2009	-5.208
2010	2.063
2011	12.258
2012	4.472
2013	4.678
2014	-0.290
2015	1.658
2016	-0.208
2017	2.569
2018	0.642
2019	3.084
2020	-22.459
2021	14.633
2022	12.305
2023	1.366
2024	1.164
2025	1.487
2026	3.110
2027	2.206
2028	2.768
2029	2.840