Year	% of expense
1990	11.751283513976041
1991	13.418001104362231
1992	12.664532194948416
1993	14.304267161410019
1994	14.162936436884513
1995	13.633310946944258
1996	13.264531795416604
1997	13.205495158645517
1998	13.538132321773363
1999	12.044853219100416
2000	11.127202510258268
2001	11.614763552479815
2002	10.653516852714858
2003	10.71071071071071
2004	11.156500019093368
2005	10.85308718668488
2006	9.83031752429878
2007	10.091450446618461
2008	10.641316179225925
2009	10.847291922364104
2010	12.002019568765212
2011	12.096125320787676
2012	10.914155972324435
2013	12.043253926913195
2014	12.153818789440733
2015	12.695965542873507
2016	12.940038759195557
2017	10.898374123717417
2018	14.083994487898192
2019	13.392112727277174
2020	12.870342959695833
2021	14.23166842263437
2022	17.785177025857337