Year	% of expense
2002	41.261461906759685
2003	43.98373022193109
2004	42.213603482106215
2005	42.724290175200665
2006	41.47232840448337
2007	41.742201715725926
2008	43.82964536979139
2009	45.7719447604705
2010	46.38454527786007
2011	44.78857277470577
2012	40.105422450058285
2013	43.41100794654763
2014	49.32004714807004
2015	50.750295850052595
2016	49.56646107088585
2017	40.809694285066186
2018	45.95368210448287
2019	49.08971624610106
2020	50.842975352267985
2021	47.46759070135846
2022	38.336254796561484