searchTopImpressionShare property
The impressions you've received among the top ads compared to the estimated number of impressions you were eligible to receive among the top ads.
Note: Search top impression share is reported in the range of 0.1 to 1. Any value below 0.1 is reported as 0.0999. Top ads are generally above the top organic results, although they may show below the top organic results on certain queries.
Implementation
core.double? searchTopImpressionShare;