Year	% of expense
1995	58.7023525519355
1996	63.94981735071119
1997	51.250168531321904
1998	49.33731354151306
2002	35.559981533000496
2003	36.90702218710451
2004	41.71219708497956
2011	45.40698894756816
2012	45.62893509392048
2013	46.52895715917225
2014	48.207507336222605
2015	46.98557504008248
2016	51.979203522099205
2017	53.38333923216288
2018	53.40208117939942
2019	53.26956706625131
2020	54.70065254812629
2021	54.28120539376098