Year	Percent
1991	55.811
1992	62.339
1993	55.021
1994	40.84
1995	38.151
1996	43.927
1997	43.741
1998	42.826
1999	43.975
2000	48.525
2001	48.102
2002	50.065
2003	50.207
2004	51.039
2005	53.992
2006	57.161
2007	57.71
2008	53.835
2009	53.245
2010	54.664
2011	55.208
2012	57.81
2013	59.131
2014	60.249
2015	61.074
2016	61.967
2017	62.363
2018	63.03
2019	63.684
2020	64.439
2021	65.209
2022	65.987