Year	% of expense
2005	28.808333627147377
2006	26.80856807851808
2007	26.03947214518708
2008	14.788487937264309
2009	12.482684315838078
2010	11.158742826739635
2011	10.375458079670555
2012	10.688415047817745
2013	9.747017664336084
2014	9.160985245261188
2015	9.6857787527691
2016	8.255040540638902
2017	7.308639820914093
2018	6.3519196997500265
2019	6.831844597432335
2020	5.519519772467793
2021	5.9744079104317995