Year	Percent
1991	41.51
1992	30.955
1993	41.344
1994	50.792
1995	51.786
1996	49.746
1997	45.147
1998	52.7
1999	50.647
2000	50.857
2001	52.154
2002	53.925
2003	52.458
2004	49.671
2005	50.316
2006	48.815
2007	48.066
2008	43.463
2009	39.557
2010	37.676
2011	39.29
2012	39.359
2013	38.137
2014	43.522
2015	42.754
2016	41.543
2017	43.654
2018	43.431
2019	43.468
2020	43.506
2021	43.614
2022	43.826