Write SQL query to solve given problem: What percentage of authors of the paper about Charged particle multiplicity are affiliated with INFN?. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT CAST((SUM(CASE WHEN T1.Affiliation LIKE '%INFN%' THEN 1 ELSE 0 END)) AS REAL) * 100 / COUNT(T2.Id) FROM PaperAuthor AS T1 INNER JOIN Paper AS T2 ON T1.PaperId = T2.Id WHERE T2.Title LIKE '%Charged particle multiplicity%'