Question: What is the average value of Adjusted net enrolment rate, primary, both sexes (%) indicator in Algeria from 1975 to 1980?
SQL: SELECT CAST(SUM(Value) AS REAL) / COUNT(CountryCode) FROM Indicators WHERE CountryName = 'Algeria' AND Year > 1974 AND Year < 1981 AND IndicatorName = 'Adjusted net enrolment rate, primary, both sexes (%)'