Each node has a score (percentage) which is updated weekly & want to show latest and the past scores in below/in a chart
You could implement them with a field_collection (currently not stable for either D7 or D8) or with the paragraphs module (currently stable for D8 only) if you need to keep track of old scores of each node and when they've been set.

I've also implemented similar things (paired values) by simply having two multivalue fields, one after the other, and letting editors keep them in sync manually, then rendering them together in a table or the alike with a custom template.

Using two simple multivalue fields (and they could be both numeric fields, if the time is something simple as the number of the week) may eventually simplify accessing such data in a view.