Year	%
2000	18.805371017807413
2001	18.427191017269
2002	18.11519253595156
2003	17.881421056569014
2004	17.637581925315235
2005	17.434797320675663
2006	17.24507418771311
2007	17.11278310754471
2008	16.92740228240238
2009	16.797268171539958
2010	16.6956515891391
2011	16.65196354786226
2012	16.600035591882058
2013	16.55533815774354
2014	16.566781919358
2015	16.55347318856663
2016	16.602777667245835
2017	16.63245189081136
2018	16.680464932293678
2019	16.76631139556168