Year	Percent
1991	55.266
1992	55.658
1993	56.44
1994	56.921
1995	57.345
1996	59.161
1997	58.712
1998	58.34
1999	58.405
2000	59.237
2001	60.011
2002	62.192
2003	62.387
2004	61.695
2005	61.57
2006	61.945
2007	62.771
2008	63.528
2009	66.555
2010	67.091
2011	66.872
2012	67.116
2013	67.296
2014	67.942
2015	68.428
2016	69.158
2017	68.963
2018	69.17
2019	69.368
2020	69.549
2021	69.744
2022	69.902