Year	Percent
1991	45.085
1992	45.019
1993	45.258
1994	45.223
1995	45.175
1996	45.146
1997	45.122
1998	45.107
1999	45.09
2000	45.098
2001	45.094
2002	45.086
2003	45.159
2004	45.394
2005	45.673
2006	45.967
2007	46.285
2008	46.626
2009	46.979
2010	47.342
2011	47.731
2012	48.113
2013	48.49
2014	48.251
2015	48.411
2016	47.145
2017	47.246
2018	47.342
2019	47.434
2020	47.531
2021	47.626
2022	47.726