Year	Percent of GDP (Units)
1980	24.250
1981	22.504
1982	25.452
1983	11.420
1984	18.113
1985	19.154
1986	20.809
1987	25.185
1988	27.882
1989	12.699
1990	10.218
1991	18.680
1992	23.721
1993	18.750
1994	14.156
1995	18.114
1996	16.555
1997	27.673
1998	30.660
1999	26.517
2000	24.170
2001	27.524
2002	21.159
2003	15.217
2004	21.798
2005	23.004
2006	26.922
2007	30.340
2008	26.826
2009	25.797
2010	21.972
2011	23.072
2012	23.803
2013	31.696
2014	19.735
2015	19.430
2016	10.245
2017	5.111