Year	% of expense
2008	11.523208531132136
2009	12.292625197841515
2010	11.232882590972412
2011	15.174119092984984
2012	21.93574105590292
2013	29.53407788587659
2014	23.2291243302952
2015	21.32858236013589
2016	18.51070850921579
2017	18.273988755159216
2018	20.93314005601983
2019	20.28501597134117
2020	32.57290276674169