Year	Percent
1991	67.399
1992	59.621
1993	61.359
1994	58.172
1995	56.261
1996	49.101
1997	40.351
1998	50.237
1999	47.913
2000	40.209
2001	42.571
2002	45.401
2003	45.496
2004	42.728
2005	44.697
2006	44.752
2007	43.499
2008	42.607
2009	44.41
2010	45.722
2011	43.558
2012	43.208
2013	44.526
2014	44.078
2015	45.934
2016	46.598
2017	46.271
2018	46.277
2019	46.271
2020	46.259
2021	46.229
2022	46.194