The top-line view of Security & Compliance | Reports offers a lot of information at a glance with very little depth. If you have yet to configure DLP or labels, the first two rows of tiles will be completely without any valuable information:
By default, the Dashboard only displays about 5 days' worth of data. This can make it exceedingly difficult to determine whether any apparent decline might just be a weekend phenomenon, as shown earlier where many metrics appear to show some improvement—until you consider that 5/5 was a Saturday and data for Monday 5/7 isn't available ...