Year	Percent change (Units)
1997	7.623
1998	5.580
1999	5.544
2000	2.797
2001	1.224
2002	5.704
2003	4.404
2004	3.007
2005	5.297
2006	3.845
2007	1.858
2008	9.891
2009	2.752
2010	3.751
2011	2.876
2012	2.781
2013	1.723
2014	1.733
2015	1.431
2016	-0.220
2017	0.213
2018	-0.195
2019	1.557
2020	-0.711
2021	1.238
2022	3.740
2023	5.872