Year	Percent change (Units)
1991	3.638
1992	3.687
1993	-3.234
1994	-2.919
1995	9.273
1996	11.364
1997	4.826
1998	1.502
1999	-6.383
2000	19.012
2001	-3.890
2002	-6.389
2003	30.604
2004	-0.125
2005	-9.774
2006	-2.574
2007	2.907
2008	-3.852
2009	4.150
2010	10.238
2011	-10.117
2012	-4.617
2013	1.938
2014	-8.507
2015	8.652
2016	-7.177
2017	8.194
2018	0.052
2019	17.775
2020	-16.658
2021	-21.372
2022	-2.079
2023	6.367
2024	2.922
2025	-1.657
2026	0.361
2027	2.142
2028	-1.116
2029	1.145