Year	Percent
1991	25.183
1992	24.842
1993	25.349
1994	27.89
1995	27.45
1996	29.922
1997	26.094
1998	26.647
1999	26.036
2000	28.661
2001	29.128
2002	28.894
2003	28.94
2004	28.801
2005	29.33
2006	29.293
2007	28.926
2008	28.484
2009	28.619
2010	28.923
2011	29.018
2012	29.015
2013	28.857
2014	28.819
2015	28.74
2016	28.698
2017	28.884
2018	28.869
2019	28.805
2020	28.735
2021	28.647
2022	28.561