Year	% of expense
1991	1.9002561517911398
1992	1.4605252593415416
1993	1.8791062825403673
1994	2.181334106353641
1995	6.079651090087066
1996	5.166180948349048
1997	5.125403358461145
1998	5.451042660575347
1999	5.481441252633194
2000	5.306304503861655
2001	5.822553936357414
2002	5.242404006869404
2003	5.710478061190955
2004	5.928859589066226
2005	6.022396831273968
2006	5.764240889801657
2007	5.496473504034224
2008	5.563510298250021
2009	6.032866631964392
2010	6.2437410477745505
2011	5.540663186120865
2012	5.924380361827679
2013	5.6713113526570424
2014	6.019166478230428
2015	5.695457856490936
2016	5.740050706445758
2017	5.996761799071601
2018	6.017267810812162
2019	5.678804401978389
2020	5.668729188115508
2021	5.7771531633808815
2022	7.370209201126289