Year	% of total
1990	76.87066523395526
1991	71.13389015439128
1992	68.91306730980048
1993	67.5925925925926
1994	67.5925925925926
1995	64.63336814015547
1996	59.10780669144982
1997	65.92177279401949
1998	65.90139652983495
1999	58.93445076324454
2000	64.8506151142355
2001	64.5602049530316
2002	66.48602395892755
2003	72.14556353559917
2004	70.49036777583187
2005	67.01211822119866
2006	69.9432581343713
2007	72.5389876880985
2008	74.03274415573837
2009	72.05387205387206
2010	68.22542286828956
2011	77.2065011571639
2012	74.30814741090929
2013	73.93122084278686
2014	67.0065179692639
2015	73.08418672695836