Year	% of expense
1993	1.6133098058986555
1994	0.6534823731728306
1995	0.7232954044279782
1996	0.9016011192289678
1997	0.3301025424919223
1998	0.6914316702820025
1999	0.6424996618422832
2005	0.2757763431269276
2006	0.04217185028993147
2013	8.814454043361138
2014	9.074695758664665
2015	8.296345346028502
2016	8.89937701133286
2017	2.390657249760838
2018	4.231256562745202
2019	2.2594149973853686
2020	4.476055889905826