Year	Percent
1991	42.809
1992	43.107
1993	42.946
1994	43.18
1995	43.273
1996	43.717
1997	44.226
1998	44.747
1999	45.872
2000	47.014
2001	48.103
2002	49.062
2003	50.027
2004	51.134
2005	52.372
2006	53.701
2007	55.037
2008	56.515
2009	57.923
2010	59.318
2011	60.681
2012	62.022
2013	63.232
2014	62.085
2015	61.151
2016	60.003
2017	60.524
2018	61.042
2019	61.548
2020	62.036
2021	62.508
2022	62.959