Year	% of total
1992	76.60915054667787
1993	79.36492903930132
1994	78.81588926174497
1995	82.91983980283425
1996	81.56464846019756
1997	82.70904337492573
1998	73.54297047970479
1999	72.061375
2000	76.97730769230769
2001	75.16270765206018
2002	75.3635127860027
2003	78.32956030897206
2004	77.89124113475178
2005	73.57561331775702
2006	75.46312146003777
2007	71.36332997481108
2008	71.57566976489885
2009	77.65411764705883
2010	79.03084216101695
2011	85.50915789473684
2012	85.92755661501788
2013	87.57613861386139
2014	90.5432098765432
2015	96.17226415094339
2016	92.03818530351438