Year	Percent
1991	38.476
1992	38.918
1993	39.001
1994	39.577
1995	39.987
1996	40.939
1997	41.017
1998	41.902
1999	40.917
2000	38.968
2001	41.347
2002	41.779
2003	42.984
2004	43.793
2005	43.332
2006	43.377
2007	43.903
2008	43.613
2009	43.586
2010	44.709
2011	45.457
2012	45.755
2013	45.726
2014	46.384
2015	46.348
2016	46.834
2017	46.497
2018	46.6
2019	46.861
2020	47.171
2021	47.419
2022	47.719