Explaining an odd quirk of the Office 365 Manager
In the Office 365 Manager, all organizations are shown on a single graph to improve visibility of overall trends.
Because organizations may have begun using Microsoft products at different times, it is possible organizations may have different amounts of Secure Score data available. A date for which an organization does not have data available is displayed as zero. Therefore the graph may show that some organizations had a secure score of zero before the first available data.