Year Percent of GDP (Units) 1990 39.384 1991 41.514 1992 36.980 1993 33.104 1994 30.902 1995 31.073 1996 28.718 1997 28.332 1998 29.397 1999 31.535 2000 31.048 2001 29.963 2002 29.488 2003 29.530 2004 30.261 2005 31.611 2006 32.497 2007 31.519 2008 30.667 2009 29.455 2010 31.210 2011 30.921 2012 31.082 2013 31.729 2014 31.772 2015 32.816 2016 29.316 2017 28.163 2018 28.990 2019 28.754 2020 28.618 2021 30.420 2022 31.044 2023 31.461 2024 30.638 2025 31.657 2026 32.035 2027 31.482 2028 31.444 2029 31.421