CREATE TABLE table_name_30 (Id VARCHAR(255))
What was the percentage in 1980 that had less than 37.8% in 2006, more than 29.4% in 2000, and more than 18.2% in 1970?
    
SQL: SELECT MIN(1980) FROM table_name_30 WHERE 2006 < 37.8 AND 2000 > 29.4 AND 1970 > 18.2