Year	%
2000	23.414136150555482
2001	23.128842563960056
2002	23.14194346682168
2003	23.114017325260455
2004	22.984187744248917
2005	22.446565199234733
2006	21.651581392926055
2007	21.11905257920884
2008	20.823656326206585
2009	20.596362889314857
2010	20.352259967223834
2011	20.09375658958315
2012	19.792712955081793
2013	19.317425475759226
2014	18.925398528617286
2015	18.654316499181245
2016	18.49756792477729
2017	18.229291491415662
2018	17.98086178643021
2019	17.878946398179373