The above are the fuel efficiency figures obtained by the three government-approved test agencies, under standard test conditions. Among other parameters, these conditions include two persons in the car, air-conditioner switched off, non-adulterated fuel, recommended air pressure in all tyres and gear changes in a pre-determined pattern, at predetermined acceleration levels.The pre-determined pattern will reflect both city and highway conditions. All cars will undergo the same test cycle, and hence the figures can be compared across vehicles.
Since real-world driving conditions rarely match ‘standard test conditions,’ most users will not be able to get fuel efficiency figures that are as good as the ones mentioned. But the advantage with this list is that you can compare each car on a "like-to-like" basis, and not be taken in by inflated claims by the dealer or the manufacturer.
And re the data being a year old, I will try and get the latest figures, but the certification data holds good till any change in the engine or vehicle, in which case the car company will have to go for re-certification.