Year	% of total
1990	89.6665508857242
1991	84.28076256499133
1992	85.04534212695796
1993	88.22393822393822
1994	87.69153056070046
1995	86.31767775603392
1996	86.19183857852734
1997	85.59334620525767
1998	83.79682179341657
1999	79.207343727233
2000	76.47922478343855
2001	87.51964790946244
2002	84.04202922344443
2003	79.2668447610567
2004	77.39613019349032
2005	78.30596369922212
2006	72.90893519840137
2007	77.0852570021545
2008	83.80605292346696
2009	77.69478617457528
2010	65.3305785123967
2011	76.47581003106968
2012	77.16384541679975
2013	66.0485723662619
2014	69.53851879419427
2015	58.3599008147361