Year	% of GDP
1972	23.04449648711944
1973	24.20741770172848
1974	24.932161778007494
1975	27.885609279889746
1976	26.823590274185204
1977	28.158218896847487
1978	31.36197109384436
1979	32.138945927446954
1980	31.309137127524362
1981	31.905333974050937
1982	34.310215635667305
1983	32.58411107778621
1984	35.478136111284385
1985	33.1747004260291
1986	33.52047371655215
1987	31.077868903463468
1988	31.495508394337573
1989	30.515438117185788
1990	30.705363499357414
1991	28.96382016493748
1992	29.437172583869604
1993	30.2768874036691
1994	31.33275999443524
1995	30.019118216258693
1996	29.598296470736322
1997	26.159156881717614
1998	26.699426039673753
1999	26.328823697998953
2000	26.476383971950234
2001	26.661605725373587
2002	27.18077152201136
2003	26.78949034862551
2004	26.507717857280795
2005	26.153184781829907
2006	26.410628504989486
2007	26.975503614796096
2008	29.176526779705174
2009	28.660549583143023
2010	27.67132752943027
2011	31.161287846582592
2012	29.876189690007347