Year	% of expense
2006	1.5085312112437639
2007	6.276744380702196
2008	1.9446474092537702
2009	12.434473437364597
2010	12.674399570258702
2011	2.218505084417248
2012	5.480258295264479
2013	5.7037897452697885
2014	2.540884859729342
2015	1.8388631141839775
2016	1.4462305965741713
2017	10.64839216864802
2018	9.466884463041023
2019	1.852571460433984
2020	4.236684973882969
2021	2.6012772614975894