Year	Percent
1991	41.391
1992	43.239
1993	43.272
1994	41.912
1995	41.335
1996	38.654
1997	37.504
1998	38.067
1999	36.73
2000	37.509
2001	38.133
2002	37.197
2003	37.43
2004	37.295
2005	38.906
2006	40.021
2007	40.833
2008	42.119
2009	41.694
2010	41.528
2011	43.652
2012	45.179
2013	45.781
2014	46.299
2015	46.749
2016	47.003
2017	47.126
2018	47.307
2019	47.394
2020	47.308
2021	47.095
2022	46.727