Year	Percent
1991	47.463
1992	46.235
1993	45.01
1994	43.199
1995	42.622
1996	42.54
1997	42.492
1998	49.711
1999	44.42
2000	44.281
2001	49.166
2002	49.058
2003	48.913
2004	50.313
2005	51.066
2006	52.392
2007	53.549
2008	53.384
2009	53.633
2010	54.625
2011	53.332
2012	51.182
2013	53.859
2014	53.798
2015	54.545
2016	54.925
2017	54.565
2018	54.736
2019	55.002
2020	55.414
2021	55.917
2022	56.527