Year	% of total primary
1971	0.529370009899139
1972	0.581160008907318
1973	0.773079991340637
1974	0.796920001506805
1975	1.26169002056122
1976	1.69228994846344
1981	0
1983	0
1986	0
2001	2.21071004867554
2002	2.525710105896
2003	2.52574992179871
2006	4.65221977233887