Year	Percent
1990	44.3
1991	44.52
1992	44.59
1993	44.84
1994	45.03
1995	45
1996	44.95
1997	44.58
1998	44.23
1999	43.89
2000	43.58
2001	43.32
2002	43.09
2003	42.88
2004	42.7
2005	42.54
2006	42.4
2007	42.28
2008	42.17
2009	42.1
2010	42.33
2011	42.48
2012	42.65
2013	43.66
2014	41.49
2015	41.94
2016	42.38
2017	42.8
2018	42.68
2019	42.53
2020	40.3