def ratingRange(app):
	""" Get the rating range of an app. """
	rating = 'Unknown'
	r = app['rating']
	if r >= 0 and r <= 1:
		rating = '0-1'
	elif r > 1 and r <= 2:
		rating = '1-2'
	elif r > 2 and r <= 3:
		rating = '2-3'
	elif r > 3 and r <= 4:
		rating = '3-4'
	elif r > 4 and r <= 5:
		rating = '4-5'
	return rating