Year	% of expense
1994	3.2894189432810985
2004	8.075757447133629
2005	8.310316032887975
2006	8.210890135729555
2007	5.659600351240522
2008	6.102693019072534
2009	10.243433564440107
2010	10.963299580027721
2011	7.436509751090013
2012	6.862080139095313
2013	6.371478474626109
2014	4.477324807709428
2015	4.292625950933635
2016	9.868385088073591
2017	6.36287036414544
2018	7.711504428113823
2019	3.881597976240835
2020	5.192942091512517
2021	3.886405062675518