Write SQL query to solve given problem: What is the percentage of the international students in University of Oslo in 2015?. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT T2.pct_international_students FROM university AS T1 INNER JOIN university_year AS T2 ON T1.id = T2.university_id WHERE T1.university_name = 'University of Oslo' AND T2.year = 2015