Year	Percent
1991	45.058
1992	45.394
1993	46.302
1994	46.01
1995	45.041
1996	45.159
1997	45.173
1998	44.663
1999	43.546
2000	43.39
2001	42.754
2002	41.953
2003	42.436
2004	42.329
2005	42.767
2006	41.996
2007	42.07
2008	40.407
2009	39.459
2010	40.273
2011	41.504
2012	41.082
2013	41.266
2014	41.562
2015	40.875
2016	40.618
2017	40.551
2018	40.61
2019	40.696
2020	40.784
2021	40.757
2022	40.603