"Cluster or Host Capacity Usage" reporting Disk Space incorrectly in Planning

Hey Forum

We run weekly reports to track the trend of CPU /  Memory / Disk Space capacity from the vCOPS report under Planning, Views, Cluster or Host Capacity Usage.  I have 2 questions:-

1. The Trend lines in the report don't not look correct to me (see below).  I believe they should look flatter as our usage peaks and troughs but the reports just show the Trend lines going upwards, any ideas why?
2. We had added storage to the clusters and rather than seeing a curved line for Disk Space capacity we just see a flat line reflecting the new Disk Space capacity (also below), why is this?

Report Period 1

Report Period 2

Thanks in advance!

Danny