Year	Percent
1991	22.417
1992	22.463
1993	22.386
1994	22.879
1995	22.792
1996	22.877
1997	23.022
1998	22.627
1999	21.997
2000	20.868
2001	20.879
2002	18.483
2003	18.584
2004	19.698
2005	19.911
2006	22.32
2007	23.798
2008	24.599
2009	22.329
2010	25.607
2011	23.487
2012	22.671
2013	23.849
2014	25.633
2015	26.315
2016	26.449
2017	26.545
2018	26.711
2019	26.827
2020	26.946
2021	27.073
2022	27.201