Year	Percent
1991	60.337
1992	61.185
1993	60.75
1994	60.624
1995	61.562
1996	60.849
1997	60.237
1998	60.825
1999	61.101
2000	60.071
2001	59.408
2002	56.041
2003	55.296
2004	53.791
2005	53.668
2006	53.411
2007	41.151
2008	41.305
2009	35.808
2010	36.025
2011	36.041
2012	35.83
2013	35.873
2014	36.151
2015	36.222
2016	36.252
2017	36.371
2018	36.361
2019	36.35
2020	36.338
2021	36.327
2022	36.316