Year	Percent change (Units)
1997	5.732
1998	-0.279
1999	2.841
2000	4.973
2001	3.212
2002	0.313
2003	0.547
2004	0.282
2005	3.582
2006	6.125
2007	1.501
2008	7.427
2009	-0.381
2010	2.124
2011	3.989
2012	2.053
2013	-0.093
2014	-0.897
2015	-1.023
2016	-1.584
2017	0.810
2018	1.417
2019	0.559
2020	-1.052
2021	1.998
2022	14.012
2023	6.098
2024	3.032
2025	2.672
2026	2.512
2027	1.987
2028	1.988
2029	1.982