Year	Percent
1991	38.543
1992	39.954
1993	41.166
1994	41.857
1995	42.839
1996	43.424
1997	43.141
1998	47.006
1999	46.872
2000	50.188
2001	51.658
2002	51.966
2003	52.462
2004	48.629
2005	50.086
2006	51.33
2007	51.396
2008	54.425
2009	55.023
2010	55.057
2011	55.345
2012	55.472
2013	56.796
2014	55.857
2015	56.061
2016	57.126
2017	57.62
2018	58.084
2019	58.608
2020	58.992
2021	59.253
2022	59.646