Year	%
2000	19.673030095514136
2001	19.58185006222215
2002	19.481785310147842
2003	19.317257054121136
2004	19.04001605379367
2005	18.652829729733423
2006	18.310635582111892
2007	17.79613290420544
2008	17.285744212621896
2009	16.99662667051068
2010	16.57629262558005
2011	16.118116666936018
2012	15.991704692317708
2013	15.757373353565253
2014	15.486486169250988
2015	15.205979960253524
2016	15.027825476653705
2017	14.819564350298037
2018	14.620813493069383
2019	14.491730979292502