Bug - Maintenance Widget - Last Backup display issue

On first install, the Maintenance widget - Last Backup correctly displays as infinite days ago with the ring chart showing 0% True (all gray). Performing a backup updates the widget to display zero (0) days ago but also shows the ring chart as still at 0% True (all gray). In contrast the Updated ring chart after updating all software displays as 100% True (all white). From a UX perspective, the user should see two 100% True ring charts, both all white, if the site is at a perfect level of maintenance (fully updated and backed up.)

The suggestion is to update the math based on:
if LastEditDate <= LastBackupDate then display True/100% else
display (LastBackupDate - Today + 7) / 7
So as each day passes, the percentage drops to 86%, 71% ... 0% after a week.

Admin plugin release 1.2.7 installed 12/26/16