Year	Percent
1991	38.314
1992	38.52
1993	38.688
1994	38.63
1995	38.303
1996	37.965
1997	37.187
1998	37.504
1999	37.833
2000	37.694
2001	38.138
2002	38.482
2003	38.862
2004	38.642
2005	39.032
2006	39.399
2007	39.727
2008	40.046
2009	40.379
2010	41.259
2011	42.591
2012	45.291
2013	44.967
2014	45.758
2015	45.448
2016	43.634
2017	43.943
2018	44.27
2019	44.66
2020	45.065
2021	45.446
2022	45.811