Hi Richard,
I'm not a There's a built-in View in vR Ops 6.1 called 'Datacenter VM Growth Trend View'. I cloned it and changed the subject to Datastore (attached). It looks like it might help but you'll want to take a look and test it out. You may find a table or dashboard with the trend widget and table more useful. You can import this into Content/Views and play around with the filters, time settings, forecast days, etc. There's a preview source option when you are modifying to help you find the right presentation. There may be better options but I hope this helps get you started in the right direction!
Bill