Year	% of expense
2001	14.19966876605521
2002	14.200491663521287
2003	9.475259269745685
2004	8.632371025988546
2005	9.873746374078522
2006	11.771216513172792
2007	11.155639133170851
2008	12.590912874911062
2009	12.001935204154243
2010	9.234207189935098
2011	13.627380435931618
2012	11.568610581945554
2013	8.564641096668224
2014	9.59370185331177
2015	9.327169062278385
2016	6.68312737031069
2017	3.8470126423243474
2018	3.423439757139272
2019	3.2849764924881777
2020	3.568940156383061
2021	6.766550484228609