### Database Schema:
CREATE TABLE matchs (
	Div	TEXT	NULL,
	Date	DATE	NULL,
	HomeTeam	TEXT	NULL,
	AwayTeam	TEXT	NULL,
	FTHG	INTEGER	NULL,
	FTAG	INTEGER	NULL,
	FTR	TEXT	NULL,
	season	INTEGER	NULL,
	foreign key (Div) references divisions (division)
);

CREATE TABLE divisions (
	division	TEXT	NOT NULL	PRIMARY KEY,
	name	TEXT	NULL,
	country	TEXT	NULL
);

### User's Query:
What is the percentage whereby the away team scored 2 goals during the 2017 seasons?

### Extra Knowledge:
scored 2 goals refers to FTAG = 2, which is short name for Final-time Away-team Goals; DIVIDE(COUNT(Div where season = 2017, FTAG = '2'), COUNT(Div where season = 2017)) as percentage;
SELECT CAST(SUM(CASE WHEN FTAG = 2 THEN 1 ELSE 0 END) / COUNT(FTAG) AS REAL) * 100 FROM matchs WHERE season = 2017