Year	Percent
1991	50.965
1992	50.841
1993	51.695
1994	53.747
1995	52.375
1996	52.147
1997	52.501
1998	54.567
1999	56.109
2000	57.348
2001	59.964
2002	60.985
2003	60.935
2004	60.415
2005	63.32
2006	64.342
2007	65.1
2008	64.498
2009	66.347
2010	68.202
2011	67.685
2012	69.071
2013	70.482
2014	71.655
2015	72.826
2016	73.706
2017	73.891
2018	74.272
2019	74.702
2020	75.375
2021	75.85
2022	76.33