Year	Percent
1991	53.67
1992	52.838
1993	51.35
1994	48.773
1995	47.226
1996	47.041
1997	46.868
1998	46.6
1999	45.915
2000	46.631
2001	46.273
2002	45.255
2003	44.817
2004	43.872
2005	43.804
2006	42.984
2007	44.259
2008	47.331
2009	46.209
2010	44.631
2011	44.053
2012	43.729
2013	43.319
2014	43.804
2015	43.368
2016	45.749
2017	45.25
2018	44.8
2019	44.403
2020	44.021
2021	43.621
2022	43.23