Year	Percent
1991	36.545
1992	38.367
1993	37.211
1994	38.971
1995	39.897
1996	41.155
1997	41.853
1998	42.268
1999	43.45
2000	43.801
2001	45.224
2002	42.949
2003	44.247
2004	44.789
2005	46.041
2006	44.176
2007	44.958
2008	47.939
2009	51.561
2010	55.168
2011	55.977
2012	53.968
2013	53.981
2014	54.702
2015	54.36
2016	54.273
2017	54.563
2018	55.038
2019	55.501
2020	55.861
2021	56.251
2022	56.598