Year	Percent
1991	25.899
1992	26.095
1993	26.548
1994	28.659
1995	25.771
1996	26.142
1997	26.423
1998	26.663
1999	25.524
2000	26.589
2001	26.64
2002	27.378
2003	26.548
2004	26.716
2005	27.196
2006	27.408
2007	28.329
2008	29.199
2009	28.636
2010	29.089
2011	28.797
2012	30.379
2013	30.551
2014	30.734
2015	29.764
2016	28.182
2017	28.073
2018	28.151
2019	28.264
2020	28.236
2021	28.237
2022	28.248