Year	Percent
1991	47.279
1992	47.606
1993	47.587
1994	47.441
1995	47.154
1996	46.726
1997	46.551
1998	46.896
1999	46.506
2000	46.451
2001	46.33
2002	46.159
2003	45.957
2004	45.769
2005	45.112
2006	45.287
2007	45.479
2008	44.859
2009	45.014
2010	44.417
2011	43.944
2012	43.91
2013	43.807
2014	43.637
2015	43.746
2016	43.889
2017	43.717
2018	43.492
2019	43.206
2020	42.901
2021	42.591
2022	42.31