Year	Percent
1991	33.551
1992	33.956
1993	34.295
1994	34.469
1995	34.79
1996	35.44
1997	35.627
1998	36.314
1999	37.107
2000	34.682
2001	33.82
2002	32.32
2003	36.819
2004	36.764
2005	38.122
2006	39.142
2007	39.863
2008	41.851
2009	42.005
2010	42.063
2011	42.035
2012	44.152
2013	43.673
2014	40.777
2015	42.056
2016	42.342
2017	42.58
2018	43.033
2019	43.236
2020	43.432
2021	43.66
2022	43.954