Year	Percent
1991	46.097
1992	37.128
1993	31.085
1994	28.559
1995	28.598
1996	27.043
1997	28.089
1998	30.512
1999	32.802
2000	33.293
2001	34.538
2002	34.772
2003	35.039
2004	35.862
2005	40.434
2006	41.382
2007	44.366
2008	44.848
2009	41.626
2010	40.256
2011	41.309
2012	42.782
2013	44.205
2014	43.45
2015	43.132
2016	43.881
2017	43.525
2018	44.094
2019	44.316
2020	44.095
2021	43.871
2022	43.691