Size facts are not the total sum of activity facts

[michaeldorner]

When I cumulatively sum activity facts I expect to get the same numbers like in size facts (documentation).

This is not true: For example, for the commits in project 716920 (which is Kubernetes and ignoring that there seems to be a crawler issue since 2019-10-01)

curl https://www.openhub.net/projects/716920/analyses/latest/activity_facts.xml

and

curl https://www.openhub.net/projects/716920/analyses/latest/size_facts.xml

I got a already some minor differences for the first months

and a significant difference for the latest ones

And both numbers do not fit to the "total number of commits" from analysis.

How come?