Year	Percent
1991	41.01
1992	40.736
1993	40.847
1994	40.495
1995	40.997
1996	41.155
1997	40.866
1998	41.306
1999	41.75
2000	42.656
2001	43.249
2002	43.8
2003	45.253
2004	44.779
2005	45.466
2006	45.58
2007	46.414
2008	46.911
2009	46.483
2010	46.303
2011	46.142
2012	46.165
2013	46.081
2014	45.783
2015	45.721
2016	45.685
2017	45.841
2018	46.054
2019	46.081
2020	46.096
2021	46.126
2022	46.17