Sometimes comparisons can be a little bit tricky to make.
Let's take the example of Office, the version installed from disk that the customer has purchased contra monthly subs for Office 365. It is not reasonable to compare the contracting sales of the product in a given year against the increase in the number of subscribers to the online version in any one year because that fails to take into account that for most customers (private or enterprise) they do not buy the latest Office package each and every time one is released. One would have to compare with, say, a three year period of subs to 365 contra sales of the latest "on disk" version for that given period. How this in fact is going to come out in the wash for Redmond I do not pretend to know - I think we need a couple more years figures before we can draw any conclusions on this particular score.