Write SQL query to solve given problem: What kind of expression correlation occurs in physical type interacting gene pairs and what percentage of these are negatively correlated?. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT Expression_Corr FROM Interactions WHERE Type = 'Physical' UNION ALL SELECT CAST(SUM(Expression_Corr < 0) AS REAL) * 100 / COUNT(*) FROM Interactions WHERE Type = 'Physical'