Year	Percent
1991	67.027
1992	66.19
1993	63.218
1994	62.643
1995	61.69
1996	59.464
1997	60.279
1998	62.509
1999	61.15
2000	59.764
2001	59.163
2002	59.422
2003	59.128
2004	55.449
2005	55.494
2006	55.637
2007	55.407
2008	56.257
2009	54.359
2010	54.376
2011	57.056
2012	57.733
2013	61.297
2014	52.216
2015	51.172
2016	52.558
2017	52.535
2018	52.476
2019	52.419
2020	52.362
2021	52.305
2022	52.247