Year	% of expense
2009	21.27458142710005
2010	20.661246687484066
2011	21.84793845319004
2012	22.974346604375363
2013	18.573313520812395
2014	21.68980899967017
2015	21.241661290618467
2016	20.638290617556393
2017	24.545499689714095
2018	20.104119223003668
2019	20.065667683256507
2020	17.316554575312686
2021	18.914289347978077