| MES | 1950 | 1951 | 1952 | 1953 | 1954 | 1955 | 1956 | 1957 | 1958 | 1959 | 1960 | 1961 | 1962 | 1963 | 1964 | 1965 | 1966 | 1967 | 1968 | 1969 | Media | |||
| Enero | 21,7 | 21,2 | 20,6 | 20,0 | 22,8 | 24,4 | 23,7 | 22,0 | 21,6 | 26,0 | 23,0 | 22,6 | 25,0 | 26,0 | 27,2 | 24,0 | 27,0 | 23,6 | 22,5 | 25,0 | 23,6 | |||
| Febrero | 23,6 | 25,3 | 24,2 | 23,4 | 21,5 | 26,6 | 23,4 | 25,5 | 26,6 | 25,0 | 30,2 | 27,6 | 24,2 | 22,0 | 29,0 | 24,4 | 28,0 | 30,2 | 20,4 | 25,0 | 25,3 | |||
| Marzo | 27,4 | 27,6 | 33,0 | 28,3 | 22,5 | 29,0 | 23,0 | 28,0 | 27,0 | 25,8 | 31,8 | 30,0 | 24,8 | 32,6 | 25,2 | 30,4 | 26,0 | 30,0 | 21,1 | 27,8 | 27,5 | |||
| Abril | 29,6 | 27,4 | 26,4 | 29,6 | 25,3 | 31,2 | 24,8 | 27,5 | 31,0 | 27,2 | 28,8 | 27,4 | 26,4 | 29,2 | 28,0 | 26,0 | 28,0 | 23,0 | 24,0 | 24,2 | 27,2 | |||
| Mayo | 30,6 | 26,0 | 26,4 | 37,9 | 32,5 | 38,8 | 35,0 | 28,0 | 23,2 | 30,2 | 27,2 | 31,2 | 36,0 | 28,2 | 38,2 | 32,6 | 26,6 | 25,0 | 24,0 | 26,2 | 30,1 | |||
| Junio | 28,4 | 30,2 | 35,2 | 28,2 | 28,0 | 31,7 | 28,0 | 28,1 | 23,0 | 30,2 | 29,2 | 28,8 | 30,2 | 28,6 | 28,2 | 30,2 | 31,0 | 28,6 | 30,0 | 29,2 | 29,3 | |||
| Julio | 35,4 | 29,0 | 43,0 | 48,0 | 38,2 | 28,8 | 32,2 | 40,6 | 32,0 | 30,8 | 29,0 | 38,0 | 31,0 | 35,0 | 28,6 | 28,2 | 27,6 | 40,0 | 32,0 | 41,0 | 34,4 | |||
| Agosto | 34,2 | 28,4 | 22,2 | 38,6 | 37,0 | 32,6 | 42,1 | 32,2 | 42,6 | 41,0 | 33,6 | 39,0 | 41,0 | 31,4 | 36,0 | 36,6 | 41,6 | 33,2 | 27,0 | 30,2 | 35,0 | |||
| Septiembre | 32,8 | 33,6 | 32,6 | 33,8 | 37,4 | 35,8 | 31,5 | 41,0 | 32,8 | 31,0 | 35,4 | 42,0 | 39,4 | 39,2 | 27,6 | 31,4 | 33,2 | 27,8 | 34,0 | 27,4 | 34,4 | |||
| Octubre | 30,9 | 27,6 | 37,2 | 29,6 | 31,8 | 30,0 | 34,5 | 29,0 | 37,2 | 29,8 | 31,0 | 30,6 | 29,0 | 27,7 | 33,6 | 29,4 | 26,8 | 28,0 | 34,2 | 26,4 | 30,7 | |||
| Noviembre | 27,2 | 24,0 | 30,0 | 27,4 | 26,0 | 27,4 | 29,0 | 26,2 | 27,0 | 26,6 | 27,6 | 26,6 | 27,0 | 31,5 | 29,4 | 26,2 | 26,4 | 25,0 | 27,0 | 27,2 | 27,2 | |||
| Diciembre | 24,3 | 21,8 | 26,6 | 24,2 | 23,0 | 23,8 | 23,0 | 23,0 | 25,8 | 24,6 | 25,0 | 29,4 | 26,0 | 24,3 | 26,0 | 25,6 | 23,2 | 22,0 | 25,0 | 20,4 | 24,3 | |||