Year	Percent
1991	25.728
1992	25.964
1993	25.774
1994	26.22
1995	25.986
1996	26.397
1997	24.143
1998	24.343
1999	24.732
2000	25.228
2001	24.969
2002	25.091
2003	22.342
2004	22.675
2005	22.641
2006	22.568
2007	22.884
2008	22.734
2009	22.179
2010	22.444
2011	22.492
2012	22.592
2013	22.619
2014	22.624
2015	22.836
2016	22.947
2017	22.945
2018	22.949
2019	22.954
2020	22.959
2021	22.963
2022	22.967