Year	% of expense
1998	10.085027678110437
1999	7.952214429444976
2009	46.039884142890436
2010	48.242081607145074
2012	21.815538156447335
2013	20.809101563363775
2014	24.1180545493161
2015	23.473681140186166
2016	25.056355012460806