Year % of revenue 1996 38.370754173862984 1997 41.05510142294884 1998 49.92520634250216 1999 42.578793361099784 2000 43.37047085453757 2001 50.22060640800372 2002 50.49093565150753 2003 43.66793365583967 2004 45.11559588724119 2005 46.655315466167465 2006 46.417332560687626 2007 45.93970416314106 2008 48.123556437891715 2009 46.02950046107163 2010 45.58881586326233 2011 51.14847992924134 2012 52.04076724768171 2013 52.01429253007215 2014 52.858113150590746 2015 46.35513421486245 2016 46.89399823934545 2017 47.71702845817355 2018 51.16815167501556 2019 46.5986671709062 2020 45.22485393992977 2021 50.673267876434224 2022 47.33387281650302