Year	%
2000	17.5300006866455
2001	16.2999992370605
2002	18.1900005340576
2003	16.9099998474121
2004	12.8999996185303
2005	19.8199996948242
2006	19.9300003051758
2007	18.3500003814697
2008	15.8699998855591
2009	21.9300003051758
2010	23.6599998474121
2011	24.8099994659424
2012	27.3700008392334
2013	28.5799999237061
2014	25.3199996948242
2015	25.4699993133545
2016	28.3099994659424
2017	28.1000003814697
2018	27.6299991607666