Year	years
2003	2.5777777777777775
2004	2.5777777777777775
2005	2.5500000000000003
2006	2.5500000000000003
2007	2.5500000000000003
2008	2.5500000000000003
2009	2.5500000000000003
2010	2.7199999999999998
2011	2.5500000000000003
2012	2.5500000000000003
2013	2.5500000000000003
2014	2.5500000000000003
2015	2.5500000000000003
2016	2.5500000000000003
2017	2.5500000000000003
2018	2.5500000000000003
2019	2.4699999999999998