Streaming show us how many people listening music now. Old hits like livin or bad name are older than KTF but they have mmoe listenings than Hand , Who Says ecc.
So you can't say that people listen music from ktf album only from cd. I think that streaming or youtube are show us better which songs are popular than amount of copy of singles/cd.
It's beacuse when they relased ktf sales of this cd was only ok at that time and they got only number 5 if i remember correctyly. THINFSale today has nr1 and beat other massive artist like for example A.Keys

So i think that we should looking on streaming for songs to see which songs are really popular. Of course we should only take views from some period time after promoting it because it's normal that new single will have more views than old in time when band promote them.

I think that we can't compare In These Arms by numbers of singles sold. We can look on streaming and comparing these 2 songs would be fair because they were relased before spootify ecc so they numbers of streaming aren' pushed by promotion, shows ecc.

Of course any method for comparing songs from 2 different music decade will be fair.