Year	Percent change (Units)
1997	22.853
1998	13.814
1999	10.750
2000	4.442
2001	2.362
2002	5.053
2003	3.858
2004	6.257
2005	4.236
2006	5.691
2007	5.979
2008	5.594
2009	-0.816
2010	0.767
2011	0.908
2012	-0.707
2013	2.351
2014	1.148
2015	4.314
2016	3.242
2017	3.244
2018	3.829
2019	2.886
2020	-3.015
2021	7.392
2022	4.227
2023	1.800
2024	2.500
2025	3.000
2026	3.000
2027	3.000
2028	3.000
2029	3.000