Year	Percent
1991	44.47683
1992	44.50498
1993	44.52122
1994	44.45725
1995	44.39768
1996	44.44606
1997	44.80036
1998	45.07116
1999	45.65213
2000	48.72316
2001	51.49126
2002	54.27825
2003	56.75512
2004	58.92778
2005	61.06217
2006	61.13917
2007	60.96677
2008	61.10387
2009	60.93248
2010	60.31326
2011	59.7386
2012	59.2182
2013	58.58597
2014	57.94248
2015	57.25473
2016	56.53449
2017	55.85856
2018	55.08075
2019	54.36277