SELECT AVG(_percentage_2006) FROM table_name_70 WHERE seats_2001 > 15 AND _percentage_2001 > 100
When seats for 2001 is greater than 15 and % 2001 is greater than 100, what is the % 2006?
CREATE TABLE table_name_70 (
    _percentage_2006 INTEGER,
    seats_2001 VARCHAR,
    _percentage_2001 VARCHAR
)