Year	Percent
1991	54.127
1992	54.395
1993	52.752
1994	48.733
1995	47.313
1996	47.184
1997	47.431
1998	47.419
1999	46.887
2000	47.856
2001	48.066
2002	44.304
2003	46.158
2004	46.987
2005	48.247
2006	49.265
2007	49.406
2008	49.506
2009	49.255
2010	50.136
2011	48.818
2012	46.799
2013	51.544
2014	47.521
2015	46.263
2016	46.005
2017	45.994
2018	45.92
2019	45.698
2020	45.201
2021	44.541
2022	43.729