Year	%
1997	15.353260869565236
1998	15.353260869565236
1999	16.304347826086946
2001	16.711956521739125
2002	16.576086956521774
2003	16.847826086956537
2004	17.496635262449537
2005	17.631224764468342
2006	18.169582772543766
2007	18.648648648648663
2008	19.11170928667567
2009	18.977119784656807
2010	18.977119784656807
2011	20.107962213225402
2012	20.75471698113206
2013	20.6756756756757
2014	21.698113207547166
2015	22.27979274611399
2016	22.178988326848273
2017	22.366710013003882
2018	24.99999999999996
2019	25.87776332899871
2020	28.14136125654453
2021	28.88601036269433
2022	29.48051948051948
2023	29.701686121919575