Year	%
1997	8.121827411167512
1998	7.437457741717374
1999	9.640190088255258
2000	9.848484848484846
2001	10.461338531513968
2002	11.66772352568167
2003	12.000000000000002
2004	12.318840579710153
2005	13.121161362367397
2006	12.40997229916898
2007	12.520961430967018
2008	13.502358490566033
2009	13.596746077861708
2010	13.461538461538462
2011	14.227405247813406
2012	14.778037383177566
2013	14.914856136230181
2014	14.863325740318903
2015	15.568181818181822
2016	16.174010039040716
2017	16.250693288962843
2018	17.36725663716814
2019	18.377483443708613
2020	19.51219512195122
2021	20.220994475138127
2022	21.130625686059275
2023	21.31147540983607