Year	% of total
1990	91.4727335880514
1991	85.30329289428076
1992	86.01813685078318
1993	89.92277992277992
1994	88.29769321434586
1995	86.93737769080235
1996	87.20072278271344
1997	86.63300163374424
1998	84.63393870601588
1999	79.76103744718054
2000	82.82190574071355
2001	90.16032694121346
2002	87.5718272861599
2003	79.60819234194123
2004	77.77111144442777
2005	78.50763468740996
2006	76.44875820725093
2007	84.45675592489998
2008	86.6899065124386
2009	81.40011716461628
2010	66.51515151515152
2011	78.7838437638704
2012	83.32801022037688
2013	73.85953396783722
2014	75.95831782657238
2015	64.06305348919588