Year	% of expense
1990	62.46079715037054
1991	51.15084421790387
1992	59.324126197744675
1993	67.5068192775668
1994	49.60256009783136
1995	58.1126624939817
1996	75.59483344663495
1997	69.91866334560363
1998	35.554648594592585
1999	51.5403323875152
2000	56.10842946776978
2001	32.98467890275204
2002	36.49906451378595
2003	54.86843349256526
2004	41.57360114335829
2005	21.985270216732385
2006	21.37244732509311
2007	22.19362020893312
2008	29.56096169052814
2009	20.951808354927344
2010	18.63157959111285
2012	42.13166487087535
2013	45.749621137052216
2014	45.456367147956946
2015	45.29940856843083
2016	42.136736823305185
2017	26.04515408231107
2018	32.041077509919106
2019	30.478507271834825
2020	26.236502732004823
2021	27.547290760385756
2022	27.481729055389888