Year	Percent
1991	56.365
1992	57.369
1993	52.864
1994	52.649
1995	51.532
1996	51.952
1997	52.702
1998	54.921
1999	53.34
2000	56.353
2001	57.234
2002	54.425
2003	54.935
2004	55.613
2005	54.443
2006	52.281
2007	51.79
2008	50.529
2009	49.008
2010	43.686
2011	40.756
2012	40.219
2013	41.194
2014	41.11
2015	41.603
2016	41.423
2017	40.433
2018	40.574
2019	40.801
2020	41.113
2021	41.504
2022	41.853