Year	Percent
1991	25.954
1992	25.905
1993	25.83
1994	25.588
1995	25.6
1996	25.552
1997	25.331
1998	25.041
1999	24.881
2000	24.502
2001	24.277
2002	24.074
2003	23.887
2004	23.685
2005	23.627
2006	23.45
2007	23.321
2008	23.389
2009	23.631
2010	23.505
2011	23.437
2012	23.471
2013	23.394
2014	23.201
2015	23.071
2016	22.946
2017	22.891
2018	22.799
2019	22.689
2020	22.543
2021	22.38
2022	22.214