Year	% of expense
2001	1.3050819334323343
2002	1.2121514796952142
2003	1.2290261255475938
2004	1.4333431990190688
2005	1.3772087516990397
2006	19.079576178297405
2007	8.437815569119133
2008	20.84736251402918
2009	2.0120081119691506
2010	8.269612138541715
2012	7.064738173046216
2013	3.3867957788725818
2014	3.7516001198387627
2015	1.9529209358696638
2016	1.5568598484345004
2017	1.923599260456726
2018	1.7868518471038604
2019	2.327905528562695