Year	Percent
1991	35.23
1992	35.94
1993	37.074
1994	38.104
1995	38.442
1996	38.842
1997	38.92
1998	40.33
1999	42.88
2000	44.863
2001	43.121
2002	43.062
2003	45.039
2004	44.493
2005	43.954
2006	44.722
2007	44.948
2008	45.599
2009	47.894
2010	48.196
2011	47.935
2012	49.475
2013	49.674
2014	48.515
2015	49.477
2016	49.003
2017	49.606
2018	50.465
2019	51.205
2020	51.734
2021	52.074
2022	52.411