Year	Percent
1991	60.122
1992	60.422
1993	60.518
1994	60.374
1995	61.144
1996	60.516
1997	60.744
1998	60.914
1999	61.109
2000	61.229
2001	61.643
2002	61.847
2003	61.536
2004	62.251
2005	62.364
2006	62.952
2007	63.344
2008	63.903
2009	64.56
2010	64.736
2011	66.709
2012	65.61
2013	66.027
2014	66.394
2015	66.554
2016	66.546
2017	67.499
2018	69.062
2019	69.441
2020	69.181
2021	68.968
2022	68.751