Year	% of expense
2002	3.4926608532165346
2003	4.202464632139562
2004	5.669603880523348
2005	4.998579718594247
2006	4.745594707088947
2007	6.311568758486256
2008	5.8739995591525584
2009	6.036332840485365
2010	6.599526605158894
2011	6.345159726194768
2012	5.353302107097123
2013	4.508294863268817
2014	4.734714977537197
2015	5.825554213807045
2016	5.6750927634767
2017	5.414004557382294
2018	6.107270420743015
2019	5.973595404447768
2020	5.939168166614886
2021	6.096211009368342
2022	8.119347718482297