Year % of GDP 1990 23.680981595092025 1991 22.35212675948004 1992 21.422098292087835 1993 21.80215475024486 1994 21.810955160849584 1995 22.233275304650586 1996 24.039448750066004 1997 22.817910641333246 1998 20.13206129465607 1999 19.153592306652776 2000 16.338461538461537 2001 17.305555555555554 2002 15.942580645161291 2003 16.29 2004 17.64774193548387 2005 19.433333333333334 2006 21.659375 2007 22.079411764705885 2008 21.010526315789473 2009 23.33888888888889 2010 26.514285714285712 2011 25.826315789473686 2012 19.624736842105264 2013 19.0145 2014 18.24418604651163 2015 15.916326530612245