Year	Percent
1991	42.11
1992	35.876
1993	36.185
1994	37.134
1995	33.765
1996	34.687
1997	36.096
1998	37.439
1999	37.495
2000	38.703
2001	40.689
2002	43.999
2003	45.348
2004	46.408
2005	46.238
2006	46.873
2007	49.216
2008	49.366
2009	50.539
2010	56.235
2011	55.576
2012	54.477
2013	58.022
2014	60.18
2015	60.162
2016	59.491
2017	59.431
2018	60.131
2019	61.129
2020	62.226
2021	63.649
2022	65.16