Year	% of expense
2002	15.43747447619587
2003	19.21376560900043
2004	18.191662127568797
2005	18.64384605101592
2006	19.148668838730224
2007	18.18680987924616
2008	24.628969437939045
2009	18.250890825666453
2010	24.192487333897418
2011	24.786507522066945
2012	28.006923520160885
2013	23.629837645977616
2014	23.441175563486567
2015	22.655081622925664
2016	20.674461142363466
2017	21.850104426698763
2018	19.709741164221047
2019	25.651595330449005
2020	28.648242550877427
2021	28.159589207059003