The Bid/Imp Ratios expandable section shows:

• Bid-to-Impression ratio – how often bids result in impressions (delivery rate).
• Bid-to-Eligible Impressions ratio – how many eligible impressions we bid on (bid rate).

Charts can be viewed in hourly increments with selectable time ranges (6, 12, 24, and 48 hours). This provides improved transparency into campaign bidding efficiency and behavior.