Year	Percent
1991	54.348
1992	54.128
1993	55.089
1994	53.06
1995	53.61
1996	53.774
1997	53.709
1998	55.481
1999	53.831
2000	52.301
2001	52.256
2002	51.766
2003	52.009
2004	51.404
2005	50.943
2006	49.963
2007	50.606
2008	49.372
2009	49.919
2010	50.074
2011	49.734
2012	50.366
2013	50.719
2014	50.935
2015	51.811
2016	51.954
2017	51.439
2018	51.458
2019	51.593
2020	51.815
2021	52.107
2022	52.464