Year	Percent
1991	43.518
1992	43.268
1993	42.994
1994	42.761
1995	42.554
1996	42.569
1997	42.668
1998	42.814
1999	42.977
2000	43.05
2001	43.186
2002	43.363
2003	43.415
2004	43.482
2005	43.561
2006	43.538
2007	43.508
2008	43.562
2009	43.734
2010	43.68
2011	43.742
2012	43.847
2013	43.954
2014	44.033
2015	44.088
2016	44.113
2017	44.042
2018	44.009
2019	44.005
2020	44.022
2021	44.03
2022	44.082