Year	% of expense
1995	29.929806969165206
1996	30.190837947920002
1997	29.679952311455526
1998	30.022805443397637
1999	31.484064813821227
2000	32.450429610046264
2001	33.75708401721842
2002	33.97232337946103
2003	36.572226656025535
2004	34.38075438075438
2005	36.98647748390037
2006	38.34076350415512
2007	38.55377020711993
2008	39.46046251072248
2009	39.65739531751702
2010	40.82762002329104
2011	42.97402038179992
2012	43.101702542563565
2013	37.477695116259916
2014	46.30103205772217
2015	44.78156400174748
2016	47.87332652797822
2017	47.31009851342881
2018	45.93133185759085
2019	48.257647248371576
2020	47.08180005345065
2021	49.04498878491744
2022	51.628348850465514