Year Percent of GDP (Units) 1980 44.320 1981 41.804 1982 36.481 1983 35.443 1984 39.428 1985 35.582 1986 29.094 1987 28.125 1988 25.666 1989 26.738 1990 38.040 1991 25.190 1992 29.425 1993 27.535 1994 27.704 1995 27.999 1996 31.826 1997 36.379 1998 30.189 1999 31.286 2000 38.233 2001 31.575 2002 25.862 2003 27.913 2004 26.411 2005 33.332 2006 36.585 2007 32.834 2008 32.158 2009 34.729 2010 33.709 2011 37.387 2012 42.926 2013 39.931 2014 35.860 2015 27.067 2016 25.210 2017 28.323 2018 31.488 2019 32.998 2020 29.367 2021 37.377 2022 35.483 2023 35.364 2024 34.667 2025 34.381 2026 34.255 2027 34.321 2028 34.140 2029 33.916