Year	% of expense
1990	0.4875992412000281
1991	0.21163655737866666
1992	0.3376231034405402
1993	1.8861779952808542
1994	1.349561789961575
1995	0.4367390484185699
1996	0.7423739490708211
1997	0.9042426172092654
1998	0.7680957782425295
1999	0.6462729766052553
2000	0.5031386066384196
2001	0.4034351119959525
2002	6.925727032251666
2003	10.091930521402666
2004	7.467730397438597
2014	8.713837298340595
2015	9.325192100743557
2016	8.509718538656967
2017	9.474917728815416
2018	5.201086441355725
2019	4.790348427837458
2020	3.8653355473051536
2021	4.714487169435515
2022	4.11069096887164