Year	Percent
1991	41.871
1992	42.571
1993	43.1
1994	43.339
1995	43.035
1996	43.224
1997	42.782
1998	42.498
1999	41.339
2000	41.586
2001	41.174
2002	41.066
2003	41.521
2004	41.287
2005	40.734
2006	41.596
2007	42.151
2008	41.227
2009	41.67
2010	46.157
2011	47.031
2012	45.998
2013	45.269
2014	44.91
2015	44.028
2016	42.931
2017	42.597
2018	41.967
2019	41.218
2020	40.462
2021	39.749
2022	39.029