Year	Percent
1991	33.178
1992	30.915
1993	33.483
1994	32.664
1995	29.509
1996	29.87
1997	29.983
1998	29.063
1999	28.824
2000	29.423
2001	29.595
2002	29.205
2003	28.71
2004	28.517
2005	26.213
2006	27.538
2007	28.27
2008	27.561
2009	28.035
2010	28.926
2011	28.77
2012	28.765
2013	27.868
2014	27.392
2015	26.982
2016	29.113
2017	30.902
2018	30.733
2019	30.58
2020	33.27
2021	32.078
2022	30.071