Year	Percent
1991	44.136
1992	43.327
1993	43.847
1994	42.167
1995	45.798
1996	46.542
1997	46.738
1998	47.319
1999	47.647
2000	49.013
2001	49.754
2002	49.048
2003	49.477
2004	48.732
2005	49.077
2006	50.033
2007	50.154
2008	50.191
2009	50.876
2010	51.636
2011	52.236
2012	54.156
2013	54.319
2014	55.19
2015	56.235
2016	57.71
2017	57.693
2018	57.82
2019	57.953
2020	58.205
2021	58.41
2022	58.592