Year	%
1990	28.125
1991	28.5714285714286
1992	29.7297297297297
1993	30.2752293577982
1994	30.379746835443
1995	31.0810810810811
1996	31.5960912052117
1997	31.8072289156627
1998	32.3636363636364
1999	32.6815642458101
2000	33.5140997830803
2001	34.0535868625756
2002	34.6180798878767
2003	35.0574712643678
2004	35.540733682706
2005	36.0576923076923
2006	36.027397260274
2007	36.0355029585799
2008	36.0558283794262
2009	36.1702127659574
2010	36.2946245383668
2011	35.9715531085111
2012	36.1351636747624
2013	36.2663032898579
2014	36.3768643142961
2015	36.5335162009258
2016	36.6991869918699
2017	36.7990112776147
2018	36.9260298243024
2019	37.096544859946
2020	37.2355042594119
2021	37.3617588274484
2022	37.4756777792191