Year	Percent
1992	46.2775
1993	46.10335
1994	46.06709
1995	46.03486
1996	46.00846
1997	45.87513
1998	45.88594
1999	45.7564
2000	45.61051
2001	45.0001
2002	44.49561
2003	44.30398
2004	44.1634
2005	44.12004
2006	44.14896
2007	43.94261
2008	43.94732
2009	43.99748
2010	43.85368
2011	43.7386
2012	43.35162
2013	42.93177
2014	42.48792
2015	42.24202
2016	42.03549
2017	41.84484
2018	41.6445
2019	41.3224
2020	40.79712
2021	40.27593