Write SQL query to solve given problem: For the donation of the project 'Awesome Audiobooks Make Avid Readers', what was the percentage of the tip in the total amount?. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT CAST(SUM(T2.donation_optional_support) AS REAL) * 100 / SUM(T2.donation_total) FROM essays AS T1 INNER JOIN donations AS T2 ON T1.projectid = T2.projectid WHERE T1.title LIKE 'Awesome Audiobooks Make Avid Readers'