Year	Percent
1991	43.921
1992	44.849
1993	45.997
1994	47.374
1995	48.054
1996	47.825
1997	47.308
1998	49.42
1999	51.885
2000	51.804
2001	52.601
2002	52.382
2003	52.582
2004	52.717
2005	53.875
2006	53.546
2007	53.451
2008	53.953
2009	52.855
2010	54.901
2011	54.522
2012	54.224
2013	54.471
2014	54.933
2015	55.725
2016	56.066
2017	56.212
2018	56.455
2019	56.658
2020	56.83
2021	57.019
2022	57.15