Year	Percent change (Units)
1991	3.333
1992	2.392
1993	-5.653
1994	4.524
1995	7.690
1996	11.833
1997	4.437
1998	-1.651
1999	-5.457
2000	18.850
2001	-4.535
2002	-11.068
2003	32.225
2004	3.192
2005	-5.061
2006	-2.905
2007	4.755
2008	-4.279
2009	2.863
2010	10.326
2011	-9.741
2012	-3.766
2013	1.945
2014	-8.454
2015	4.103
2016	-10.445
2017	8.007
2018	2.937
2019	18.051
2020	-19.278
2021	-19.502
2022	-1.210
2023	3.379
2024	2.413
2025	-3.087
2026	-0.704
2027	1.351
2028	-3.136
2029	-1.286