I created the FlexView that you mentioned to provide the time that a port has been in it's current state. There is really no way to provide historical information using FlexViews (you can export the FlexView data, but then you would have to do some manual work to get the information that you want).
It sounds like you would have to have OneView (Extreme Management) collect interface stats. One piece of information that can be reported on is the Availability. Here is a KCS article that explains how to set this up:
You can then run custom reports against the interface in question to get historical availability.