Year	Percent change (Units)
1980	7.593
1981	-11.650
1982	2.513
1983	-0.244
1984	13.152
1985	12.631
1986	24.568
1987	13.407
1988	-1.594
1989	9.794
1990	18.623
1991	10.657
1992	7.981
1993	11.825
1994	15.551
1995	-5.448
1996	-1.091
1997	5.596
1998	6.698
1999	1.172
2000	-1.815
2001	0.742
2002	-4.508
2003	5.781
2004	11.579
2005	11.239
2006	9.258
2007	7.899
2008	7.363
2009	5.867
2010	-0.182
2011	13.793
2012	4.812
2013	3.380
2014	2.612
2015	-0.294
2016	-1.345
2017	0.489
2018	-6.533
2019	0.358
2020	-6.044
2021	0.564
2022	7.261
2023	1.366
2024	1.164
2025	1.487
2026	3.110
2027	2.206
2028	2.768
2029	2.840