### Database Schema:
CREATE TABLE Genes (
	GeneID	TEXT	NOT NULL,
	Essential	TEXT	NOT NULL,
	Class	TEXT	NOT NULL,
	Complex	TEXT	NULL,
	Phenotype	TEXT	NOT NULL,
	Motif	TEXT	NOT NULL,
	Chromosome	INTEGER	NOT NULL,
	Function	TEXT	NOT NULL,
	Localization	TEXT	NOT NULL,
	foreign key (GeneID) references Classification (GeneID)
);

CREATE TABLE Classification (
	GeneID	TEXT	NOT NULL	PRIMARY KEY,
	Localization	TEXT	NOT NULL
);

CREATE TABLE Interactions (
	GeneID1	TEXT	NOT NULL	PRIMARY KEY,
	GeneID2	TEXT	NOT NULL	PRIMARY KEY,
	Type	TEXT	NOT NULL,
	Expression_Corr	REAL	NOT NULL,
	foreign key (GeneID1) references Classification (GeneID),
	foreign key (GeneID2) references Classification (GeneID)
);

### User's Query:
What kind of expression correlation occurs in physical type interacting gene pairs and what percentage of these are negatively correlated?

### Extra Knowledge:
If the Expression_Corr value is negative then it's negatively correlated. Percentage of Negative Correlation = count(negative Expression_Corr physical type) / count(Expression_Corr physical type) * 100%
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'