Year	%
1990	23.2558139534884
1991	23.3333333333333
1992	24.0963855421687
1993	23.728813559322
1994	23.3532934131736
1995	23.5807860262009
1996	23.7179487179487
1997	23.8770685579196
1998	23.6427320490368
1999	23.1552162849873
2000	22.4862888482633
2001	21.980198019802
2002	21.8323586744639
2003	22.085201793722
2004	22.7110582639715
2005	23.7192118226601
2006	25.1439539347409
2007	26.5672205438066
2008	28
2009	29.2357773988529
2010	30.335322534811
2011	31.1535443369082
2012	31.6270127373228
2013	31.840300818403
2014	31.8714941356451
2015	31.8491208167896
2016	31.9259585720582
2017	32.1603859911821
2018	32.4506461587251
2019	32.7604562737643
2020	32.987430575855
2021	33.1804065499718
2022	33.4308257379948