As a comment to the last to posts,
firstly, I thought I wrote that they are start of production dates. That means that that is the date (year in this case) where the production starts for that item. As you can imaging, start of sales has to happen after the start of production in order to have something to sell
Concerning the stated power and displacement figures, bear in mind that the power figure only means something together with a power curve, torque curve and the general engine feel. The feel of the engine and the way that it performs can often mask the raw data. - more than the sum of all its parts etc.
There is also a 140hp engine listed, presumably a new Cooper - which is a real improvement.