Year	% of expense
1995	17.938552506207923
1996	17.05106950133281
1997	15.93131504729578
1998	15.404275250328304
1999	14.489580998061449
2000	14.414893276379914
2001	13.846326946624673
2002	12.85145491584332
2003	11.388599200459936
2004	10.628677527531774
2005	9.154859657000257
2006	9.307592008794598
2007	8.921666202019123
2008	8.430763745487498
2009	7.666994952203576
2010	7.2826181053477645
2011	7.086383914404397
2012	6.942725811454838
2013	6.554787825337556
2014	6.45319883149514
2015	6.2753713828110405
2016	5.866953648730099
2017	5.24389263201818
2018	4.712946490599553
2019	4.390532588229627
2020	3.8885121301762
2021	3.481573348005113
2022	3.110999527012941