Year	Percent
1991	21.352
1992	22.869
1993	24.468
1994	26.127
1995	27.82
1996	29.501
1997	31.187
1998	32.886
1999	34.627
2000	36.439
2001	38.684
2002	41.011
2003	43.409
2004	45.843
2005	48.292
2006	50.756
2007	49.901
2008	49.085
2009	48.263
2010	47.48
2011	46.685
2012	45.887
2013	45.079
2014	44.128
2015	41.818
2016	39.854
2017	40.324
2018	40.753
2019	41.14
2020	41.489
2021	41.797
2022	42.074