Year	Percent change (Units)
1980	-3.576
1981	2.472
1982	-2.468
1983	6.035
1984	12.974
1985	4.388
1986	5.501
1987	-0.295
1988	0.296
1989	-5.706
1990	0.419
1991	-4.300
1992	6.600
1993	-10.378
1994	-41.890
1995	24.541
1996	11.596
1997	14.900
1998	8.340
1999	3.308
2000	8.374
2001	8.486
2002	13.174
2003	2.219
2004	7.438
2005	9.341
2006	9.209
2007	7.684
2008	11.154
2009	6.257
2010	7.328
2011	7.966
2012	8.639
2013	4.730
2014	6.154
2015	8.867
2016	5.969
2017	3.931
2018	8.539
2019	9.472
2020	-3.380
2021	10.880
2022	8.158
2023	6.949
2024	6.931
2025	6.993
2026	7.297
2027	7.265
2028	7.265
2029	7.300