Year	Percent
1991	25.273
1992	25.217
1993	25.43
1994	25.776
1995	25.645
1996	24.208
1997	23.965
1998	24.847
1999	24.538
2000	23.927
2001	24.409
2002	24.982
2003	24.388
2004	26.204
2005	28.942
2006	30.692
2007	32.81
2008	34.419
2009	36.983
2010	37.501
2011	36.921
2012	38.412
2013	38.61
2014	45.281
2015	45.897
2016	45.432
2017	45.2
2018	44.668
2019	44.805
2020	45.138
2021	45.337
2022	45.459