AÑO	Pesetas/kilo
1967	235,5
1968
1969
1970	750,0
1971	825,0
1972	825,0
1973	1012,0
1974	1700,0
1975	1980,0
1976	1483,1
1977	1641,3
1978	1710,0
1979	1386,0
1980	1170,4
1981	1333,0
1982	1165,0
1983	1950,0
1984
1985	14000,0