Year	% of expense
1999	11.096292172597247
2000	4.085921186958438
2001	5.23956073332211
2002	3.1879528093405147
2003	1.5323492460180281
2004	2.7196516502818935
2005	3.50801353146379
2006	3.0779041101857274
2007	2.362046633284411
2008	1.6696449810039335
2009	1.1538413454737213
2010	1.108892555267008
2011	1.0746298108357077
2012	1.6309565927380674
2013	0.9229517947402215
2014	2.501458996721934
2015	2.1761815825979767
2016	1.9260170681281366
2017	2.9051364237314776
2018	1.1400529956929877
2019	2.065122191034249