Year	%
1990	36.6197183098592
1991	37.1681415929204
1992	37.1428571428572
1993	37.6923076923077
1994	37.8016085790885
1995	38.2066276803119
1996	38.2570162481536
1997	38.5780885780886
1998	38.7189292543021
1999	38.961038961039
2000	39.2045454545455
2001	39.5156150414277
2002	39.7562391178178
2003	39.989350372737
2004	40.2072027627035
2005	40.4333794375288
2006	40.6574394463668
2007	40.9815950920245
2008	41.4102064666926
2009	41.9366852886406
2010	42.3529411764706
2011	42.8277986990757
2012	43.3003300330033
2013	43.6520626798849
2014	44.0361258175023
2015	44.41400304414
2016	44.7195704057279
2017	45.0146627565982
2018	45.2786601212821
2019	45.4907539118065
2020	45.7263751763047
2021	45.9557794570389
2022	46.1752433936022
