Year	Percent
1991	58.798
1992	49.006
1993	39.528
1994	38.786
1995	38.781
1996	38.079
1997	38.53
1998	40.903
1999	43.348
2000	45.057
2001	43.473
2002	40.96
2003	40.776
2004	37.232
2005	41.373
2006	40.385
2007	42.63
2008	42.865
2009	37.904
2010	38.567
2011	40.669
2012	38.762
2013	40.817
2014	42.308
2015	43.35
2016	44.143
2017	44.595
2018	44.389
2019	43.58
2020	42.496
2021	41.645
2022	41.081