Year % of revenue 1993 31.71426270100891 1994 32.05093858981228 1995 30.259657297459793 1996 31.5544811235292 1997 31.02824866013943 1998 30.85239210488663 1999 32.5274959350748 2000 31.896103117669334 2001 26.78351700441351 2002 26.103173845560967 2003 23.670932851638053 2004 27.509960671922286 2005 27.430314930314932 2006 26.52236427585306 2007 26.960969378103666 2008 26.62530339470447 2009 28.188625665207578 2010 28.514805297363736 2011 29.864481840324025 2012 30.89468130486518 2013 31.38373562561947 2014 29.85335634192305 2015 30.323963255254505 2016 30.29350145290104 2017 30.094774272878606 2018 28.492569671291534 2019 28.348226430004033 2020 26.9954043082141 2021 26.503940159934025 2022 25.529695945145885