Year % of GDP 1974 8.732911915348323 1975 10.112372114348137 1976 10.62936618619248 1977 10.505316503091716 1978 11.269943897088558 1979 12.314447745981392 1980 11.7024781243222 1981 11.376033867530406 1982 11.963343409569653 1983 12.079891218438716 1984 13.146200295804597 1985 14.385489279766121 1986 15.34055076040377 1987 15.767218920059673 1988 15.525263555449166 1989 15.97622228151922 1990 15.821342530811076 1991 15.713364152475092 1992 15.444239761394229 1993 15.429197561408811 1994 14.961687978499889 1995 14.681060999408157 1996 14.488929716689151 1997 15.408908462031391 1998 15.15545322079527 1999 15.458871635923764 2000 15.39985796917402 2001 15.207114236654695 2002 15.62678660963022 2003 15.120418026851903 2004 14.715113142699504 2005 14.800043128513712 2006 14.904773080762842 2007 14.984977134451606 2008 16.97319082702349 2009 16.687258365830967 2010 16.225430717478382 2011 14.55119679416365 2012 15.815676980456889 2013 16.171893715092516 2014 14.621784946023727 2015 14.899161410295976 2016 14.946649316534105 2017 15.195562845610436 2018 15.056063634945426