Year	% of expense
2008	13.105939991026943
2009	9.652276475782351
2010	11.819516197015549
2011	11.925902057966423
2012	12.02053747661699
2013	15.858190888053198
2014	14.186455047116905
2015	15.358722756724482
2016	13.422973779441138
2017	15.161195527809376
2018	12.036952446460077
2019	15.956988676384148
2020	21.27380232521255