Year	Percent
1991	62.4
1992	62.821
1993	62.598
1994	62.639
1995	62.518
1996	62.022
1997	61.65
1998	61.505
1999	63.335
2000	61.933
2001	61.938
2002	64.24
2003	62.312
2004	57.004
2005	56.3
2006	54.851
2007	54.023
2008	50.544
2009	48.025
2010	39.531
2011	42.187
2012	44.694
2013	46.672
2014	45.247
2015	44.826
2016	44.896
2017	45.262
2018	45.156
2019	44.888
2020	44.351
2021	43.768
2022	43.234