Year	Percent
1991	58.976
1992	61.263
1993	63.923
1994	64.227
1995	64.628
1996	63.809
1997	63.919
1998	64.943
1999	64.955
2000	64.459
2001	64.834
2002	65.613
2003	66.112
2004	66.189
2005	65.724
2006	65.731
2007	64.973
2008	64.129
2009	60.091
2010	55.366
2011	52.471
2012	47.47
2013	47.074
2014	46.086
2015	45.092
2016	44.697
2017	44.631
2018	44.302
2019	43.858
2020	43.302
2021	42.669
2022	42.084