Year	Percent change (Units)
1990	10.100
1991	-30.175
1992	0.233
1993	-7.377
1994	-13.923
1995	-11.771
1996	-5.296
1997	-1.322
1998	6.323
1999	-7.677
2000	3.548
2001	-7.496
2002	-1.303
2003	18.344
2004	5.991
2005	12.156
2006	20.938
2007	15.694
2008	8.079
2009	-19.071
2010	-17.986
2011	30.176
2012	18.990
2013	6.645
2014	-21.210
2015	-6.178
2016	-4.756
2017	50.380
2018	-3.353
2019	13.211
2020	-29.363
2021	57.432
2022	-11.724
2023	-4.825
2024	13.341
2025	2.025
2026	4.618
2027	3.487
2028	3.345
2029	1.474