Year	Percent
1991	48.483
1992	47.089
1993	45.373
1994	44.09
1995	43.617
1996	43.449
1997	44.11
1998	45.066
1999	45.753
2000	45.806
2001	47.093
2002	43.654
2003	43.677
2004	42.044
2005	41.68
2006	41.395
2007	42.416
2008	43.24
2009	44.247
2010	44.822
2011	44.94
2012	44.894
2013	44.33
2014	43.654
2015	42.929
2016	42.217
2017	41.977
2018	41.818
2019	41.715
2020	41.663
2021	41.707
2022	41.798