Year	Percent
1991	48.171
1992	49.484
1993	50.367
1994	51.056
1995	50.541
1996	50.953
1997	50.502
1998	50.611
1999	51.902
2000	51.54
2001	53.184
2002	53.178
2003	53.49
2004	54.501
2005	55.116
2006	55.149
2007	54.746
2008	55.113
2009	56.387
2010	58.098
2011	58.312
2012	58.439
2013	58.268
2014	59.432
2015	59.9
2016	59.916
2017	59.764
2018	60.108
2019	60.473
2020	60.754
2021	60.977
2022	61.152