Year	% of expense
2013	27.05595897660087
2014	26.941985437250075
2015	28.235092791029764
2016	29.834848572204166
2017	30.116072381422633
2018	29.880942988786423
2019	32.11503291816846
2020	34.789580875124976
2021	36.54416802188314
2022	36.62889142050499