Year	% of expense
1999	13.880504734551414
2000	14.902420718885459
2001	16.51474255069359
2002	17.080170102596558
2003	17.532082539176443
2004	15.709536919744115
2005	12.831056168392688
2006	13.074885660929029
2007	13.637172005875115
2008	13.035667592455177
2009	12.90665275297459
2010	12.260529567822612
2011	11.625899373119575
2012	11.00225586196496
2013	11.592682146325561
2014	10.563309650614897
2015	11.249409731553515
2016	13.645701913393
2017	14.0044694095774
2018	14.96829635053832
2019	16.59519099990736
2020	15.857696168823798
2021	14.975437362544264
2022	33.07884074392333