Year	Percent
1991	22.794
1992	22.498
1993	22.632
1994	25.569
1995	24.873
1996	23.929
1997	22.789
1998	22.994
1999	23.434
2000	22.869
2001	23.302
2002	23.398
2003	24.346
2004	23.849
2005	23.099
2006	22.767
2007	22.689
2008	22.604
2009	22.644
2010	22.65
2011	22.719
2012	22.81
2013	23.241
2014	24.379
2015	24.767
2016	25.659
2017	26.276
2018	25.48
2019	26.057
2020	25.778
2021	25.603
2022	25.562