Year	% of expense
1992	0.8827158939229859
1995	7.926244808044798
1996	4.8633813559926145
1997	0.9359792553539485
1998	10.437184827125066
1999	7.060519968956385
2000	3.7482886031111136
2001	3.450254419032396
2002	3.4926608532165346
2003	3.2175863496904378
2004	2.927950028715055
2005	2.9517008294045444
2006	3.306783757962104
2007	3.2228797188647693
2008	3.3635233755278917
2009	3.528939339853691
2010	4.08111838158123
2011	4.478954106687681
2012	4.346657408790344
2013	4.106115311040568
2014	3.777237699766378
2015	5.633519401925678
2016	5.740050706445758
2017	5.38529989986268
2018	4.788374982949938
2019	4.434469564340544
2020	4.666339796229847
2021	3.779254624179996
2022	4.271931706131441