Year	Percent
1991	44.81165
1992	44.55314
1993	44.45698
1994	44.29512
1995	44.05095
1996	43.75837
1997	43.70153
1998	43.52915
1999	43.26784
2000	43.01151
2001	42.74752
2002	42.50358
2003	42.08849
2004	42.56603
2005	43.06613
2006	43.39169
2007	43.64054
2008	44.69917
2009	43.30766
2010	43.3895
2011	43.49335
2012	42.88809
2013	42.23655
2014	42.23319
2015	41.00995
2016	42.27738
2017	39.85873
2018	37.41643
2019	36.8435