Year	Percent
1991	14.556
1992	16.951
1993	19.775
1994	18.44
1995	19.24
1996	18.632
1997	21.248
1998	22.04
1999	21.718
2000	26.576
2001	24.775
2002	26.533
2003	28.339
2004	33.178
2005	37.13
2006	40.039
2007	41.247
2008	42.312
2009	46.883
2010	44.852
2011	45.502
2012	47.957
2013	49.056
2014	50.056
2015	52.752
2016	55.432
2017	55.258
2018	56.436
2019	57.078
2020	57.855
2021	58.655
2022	59.491