Year	% of expense
2010	26.50726790633624
2012	22.20269685566479
2013	22.864813743434397
2014	23.441175563486567
2015	23.473681140186166
2016	24.466547007449975
2017	21.768317738934112
2018	20.39906115709516
2019	23.347680656396072
2020	29.730731000777645