Year	% of expense
1990	5.616813438910678
1991	7.240931942267149
1992	9.171217954457278
1993	13.43582210515652
1994	19.19943820224719
1995	14.747467642093415
1996	15.547768043387567
1997	13.514099469553528
1998	10.450707823804713
1999	9.54461931012158
2001	10.754601288662384
2002	8.614831274154641
2003	8.718128975840607
2004	7.8219294517637055
2005	6.9912076463980215
2006	19.233298211979815
2007	18.208982538037258
2008	4.897778674342641
2009	3.3690986602001787
2010	3.2700546563613417
2011	3.676399979682864
2012	3.999747121531811
2013	3.5457592213107327
2014	3.7566330319856003
2015	3.963348686480259
2016	4.57051911671548
2017	4.206112866628877
2018	4.661240330275705
2019	5.138324290043291
2020	4.7666256062701775
2021	7.025824190434044
2022	10.153952027424488