Year	Percent
1991	39.281
1992	40.11
1993	40.923
1994	41.946
1995	42.829
1996	43.334
1997	43.268
1998	43.42
1999	43.6
2000	43.75
2001	43.686
2002	43.592
2003	43.871
2004	44.189
2005	45.442
2006	45.467
2007	45.866
2008	46
2009	46.306
2010	46.858
2011	45.67
2012	46.068
2013	46.184
2014	46.497
2015	46.615
2016	45.764
2017	45.344
2018	44.951
2019	44.541
2020	44.13
2021	43.405
2022	42.718