Year	% of expense
2007	6.311568758486256
2008	6.214399545576471
2009	6.916284778093068
2010	6.828806603493794
2011	5.969267113676015
2012	5.866612778354465
2013	5.621992933026272
2014	4.734714977537197
2015	5.7530716466831455
2016	5.2080235780678645
2017	5.201584202524674
2018	4.71132417141044
2019	4.790348427837458
2020	5.939168166614886
2021	6.067453174923218