Year	% of expense
1998	1.1668872909586048
1999	3.9467869394979727
2000	-2.15740962073807
2003	12.356128780364642
2008	17.854549888743122
2009	16.261709203024598
2010	18.288653179143033
2011	21.28937221177039
2012	9.892925241763685
2013	14.872677581121405
2014	10.708299255161451
2015	5.825554213807045
2016	20.11977908020289
2017	9.565384917782854
2018	9.865999957850798
2019	13.260086592384312
2020	13.142455669511019
2021	12.949773094980872
2022	10.668130899834594