Year	% of expense
2003	14.379399144719393
2004	13.47301379100121
2005	15.162799969124594
2006	14.514670322618214
2007	14.196045244360949
2008	14.308962662163328
2009	15.401587143822896
2010	14.701925388125826
2011	15.830655689460075
2012	16.62406389346132
2013	17.196325206438814
2014	18.507196016670605
2015	17.890857022350325
2016	18.029339539730447
2017	17.636274221047437
2018	15.915825272782666
2019	15.9119571576146
2020	15.792255893493614
2021	16.396670710749135