Year	% of revenue
1999	4.1069959115436285
2000	4.1408351854018015
2001	4.24837002566212
2002	4.159780150867727
2003	5.410534750595166
2004	5.45546886984172
2005	4.897248621246372
2006	4.256441064623479
2007	4.451554337069799
2008	3.7410411025688863
2009	2.201483549477402
2010	2.4532487645335017
2011	2.5267644163665723
2012	2.53681390968548
2013	2.546413178386275
2014	2.0803014853701822
2015	5.712665425961771
2016	2.803061233030738
2017	2.5519419784125397
2018	2.428113385481057
2019	2.4124513009444084
2020	2.2346477097449515
2021	2.3318049337518003
2022	1.1915953875670537