Year	% of expense
2002	6.671661691964401
2003	6.560752431196722
2004	6.535861384629367
2005	5.494428190143661
2006	4.49811252796251
2007	2.904811547190416
2008	2.7981304752237537
2009	3.380450237334932
2010	4.029398326103242
2011	4.503207195815706
2012	5.0449293819222705
2013	4.24376877402402
2014	4.963860828035562
2015	4.739154491948437
2016	5.837132385804952
2017	4.5898074715673784
2018	6.342503208325727
2019	6.690701593723452
2020	7.984264958759783
2021	9.696176645997713
2022	9.081860678399321