Year	Percent
1991	38.384
1992	43.913
1993	37.046
1994	30.914
1995	32.765
1996	35.062
1997	37.6
1998	35.463
1999	37.149
2000	38.533
2001	38.538
2002	38.962
2003	40.964
2004	43.241
2005	44.219
2006	46.226
2007	48.292
2008	48.177
2009	48.882
2010	46.903
2011	48.014
2012	48.407
2013	48.785
2014	51.377
2015	52.39
2016	54.181
2017	53.304
2018	54.274
2019	55.1
2020	55.967
2021	56.74
2022	57.441