year	dde
1967	44
1967	95
1968	121
1971	125
1971	95
1972	87
1976	13.3
1976	16.4
1976	50.4
1976	59.8
1976	56.4
1977	0.6
1977	23.8
1980	16.6
1980	14.5
1980	24
1981	7.8
1981	48.2
1981	53.4