Year	Percent
1991	43.047
1992	42.393
1993	42.313
1994	40.773
1995	41.672
1996	40.514
1997	41.713
1998	44.155
1999	42.381
2000	43.413
2001	42.062
2002	42.554
2003	42.625
2004	41.114
2005	40.214
2006	43.983
2007	42.833
2008	43.277
2009	40.979
2010	43.914
2011	44.238
2012	43.425
2013	43.375
2014	42.689
2015	42.359
2016	42.089
2017	42.035
2018	41.977
2019	41.917
2020	41.855
2021	41.79
2022	41.724