Year	% of expense
1992	60.83146307577215
1993	63.560467281299736
1994	55.62358651883722
1995	55.81988664010205
1996	56.41492358222918
1997	51.13276044299435
1998	54.546240226779055
1999	53.362530889873014
2000	55.86064212919211
2001	52.87087809153317
2002	51.93966408613545
2003	30.62402776159966
2006	46.92928053857036
2007	36.41827608425254
2008	39.95355718411342
2009	44.556529977025455
2010	41.982176179904314
2011	48.94372801111195
2012	48.7034720213236
2013	60.921506784603416
2014	53.03699494895976
2015	53.43756267895806
2016	54.72006934944042
2017	51.22213890988181
2018	54.85697297398981
2019	60.316791767636815
2020	63.16830138950266
2021	72.30868124661241