Year	% of total
1990	58.98691984250367
1991	57.32295423638431
1992	50.55619125135079
1993	50.89359425094132
1994	52.039369806658826
1995	51.89788352113098
1996	52.86360781721353
1997	51.02167737666902
1998	48.270802079355214
1999	48.14182518981261
2000	46.89254378978795
2001	45.94283927509539
2002	47.6618902360081
2003	49.834981989735326
2004	50.799475423610374
2005	52.30086638868963
2006	53.461336280250976
2007	51.505943619401314
2008	55.92666272096618
2009	53.285141632153376
2010	55.450253633630886
2011	57.24018188442272
2012	57.47611298110685
2013	55.30851269328039
2014	55.05152581146056
2015	55.037973207683564
2016	53.840277177446694