Year	% of expense
2005	42.06154408817028
2006	40.5770877187943
2007	43.143506071219726
2008	45.236259639407
2009	44.229151121063985
2010	42.03581725411116
2011	46.87321264418924
2012	46.5269545620527
2013	47.245549686478014
2014	50.12913291309017
2015	47.14697825236755
2016	47.222360137363346
2017	47.733210434159936
2018	46.492123097589186
2019	46.05911900896905
2020	47.34232030909282
2021	46.63596818511411
2022	47.42009377161807