Year	% of expense
2007	1.9555114179077209
2008	1.4550654179077689
2009	1.9296257780690191
2010	2.739607535073486
2011	3.2937016259140632
2012	4.562642964941736
2013	5.483146370662459
2014	6.518890292773206
2015	7.299991742943187
2016	7.36808091224345
2017	6.692649968198476
2018	5.819027877752505
2019	5.344557602360189
2020	4.255727165556583
2021	4.357533891887693
2022	3.996191719260373