Year	Percent
1991	26.427
1992	27.849
1993	23.313
1994	23.437
1995	16.036
1996	14.589
1997	15.096
1998	17.412
1999	17.235
2000	15.907
2001	15.913
2002	17.21
2003	17.185
2004	19.749
2005	20.247
2006	21.446
2007	22.698
2008	23.616
2009	25.513
2010	25.556
2011	23.83
2012	24.541
2013	24.334
2014	24.801
2015	25.977
2016	26.938
2017	26.3
2018	26.565
2019	26.89
2020	27.28
2021	27.671
2022	28.106