Year	Percent
1991	49.925
1992	49.979
1993	50.473
1994	51.008
1995	50.693
1996	50.089
1997	49.469
1998	49.194
1999	49.294
2000	48.634
2001	53.998
2002	53.906
2003	53.6
2004	52.205
2005	50.749
2006	50.118
2007	50.177
2008	50.192
2009	43.35
2010	43.939
2011	43.998
2012	43.907
2013	43.647
2014	43.205
2015	42.727
2016	42.298
2017	42.07
2018	41.751
2019	41.491
2020	41.218
2021	40.951
2022	40.696