Year	Percent
1991	38.813
1992	39.857
1993	42.62
1994	44.219
1995	43.945
1996	47.708
1997	44.386
1998	46.028
1999	45.375
2000	46.972
2001	51.644
2002	50.845
2003	50.667
2004	50.351
2005	50.391
2006	50.156
2007	49.337
2008	48.09
2009	49.051
2010	51.044
2011	53.289
2012	54.679
2013	55.476
2014	54.566
2015	54.7
2016	54.785
2017	55.538
2018	55.881
2019	56.176
2020	56.444
2021	56.684
2022	56.933