Consistent columns headers in model history

Description

Currnently, the columns headers seen in model history are dynamic and change depending on what is in the history. We would like the column headers to be consistent and not change depending on what is in the history. 

Example of Enhancement

All column headers remain the same, regardless of the content.

Benefit / Impact

This would allow for easy analysis of the history especially when importing back to Anaplan/other applications.