Year % of revenue 1990 14.926975945017182 1991 28.09496890898813 1992 38.0659253375695 1993 46.47482014388489 1994 65.70474281897127 1995 59.885087490206324 2003 10.957958812922818 2004 14.454348434131065 2005 15.821019524063853 2006 11.222760767624226 2007 6.982587937241576 2008 4.079343715952061 2009 6.975098173738672 2010 5.739786843770317 2011 5.388831942236633 2012 5.554907550508522 2013 4.259143788441418 2014 4.184375363770403 2015 6.28182082607575 2016 5.667068401874147 2017 5.1883524410463 2018 5.448404120878951 2019 4.7525648524956425 2020 5.574217008862659 2021 5.413625248124974 2022 4.815626447630396