Year	Percent
1992	20.41446
1993	19.37608
1994	20.00398
1995	18.43483
1996	15.33436
1997	17.78632
1998	20.96743
1999	25.23926
2000	22.71472
2001	21.37945
2002	15.93461
2003	15.62871
2004	15.93357
2005	20.34828
2006	18.06372
2007	9.9925
2008	4.27313
2009	9.79948
2010	12.13087
2011	13.68761
2012	12.02708
2013	15.26603
2014	16.44328
2015	18.3474
2016	24.34815