Year	% of expense
1990	12.410126469170946
1991	19.499531037055846
1992	10.201225486893296
1993	10.444168573305136
1994	11.206598583368319
1995	12.40979242163168
1996	12.77702100906376
1997	8.166157786207414
1998	10.826275251486994
1999	10.74234561932176
2000	10.21085492019231
2001	10.893308352807447
2002	10.556976379530694
2003	8.840798187800978
2004	10.556290726526207
2005	10.759957540499688
2006	10.460283225493638
2007	11.74946256014573
2008	11.462049212342142
2009	11.231354297161518
2010	11.466257503283169
2011	11.501330560432882
2012	11.519719671816807
2013	11.871996368633619
2014	10.820175158165606
2015	12.30628703103839
2016	11.761686811267053
2017	11.564091546598862
2018	11.645339584495003
2019	12.236846453443633
2020	11.30680804895884
2021	12.835732324504992
2022	11.688327226176277