Year	Percent
1991	32.39
1992	23.545
1993	23.447
1994	26.211
1995	29.778
1996	25.005
1997	24.699
1998	22.694
1999	23.107
2000	23.145
2001	22.663
2002	27.569
2003	27.438
2004	28.171
2005	28.999
2006	28.191
2007	27.471
2008	25.905
2009	25.785
2010	25.225
2011	24.422
2012	26.03
2013	25.53
2014	26.434
2015	25.246
2016	24.858
2017	25.025
2018	24.866
2019	24.549
2020	24.252
2021	23.946
2022	23.595