You might analyze exact match impression share data to get an idea of:
- the percentage of eligible impressions you received for searches that exactly matched content on your landing page
- the percentage of eligible impressions you received for searches that exactly matched your keywords
- the number of times your ads were shown on the Search Network
- the number of eligible impressions your broad match keywords received
Explanations:
Exact match impression share is a percentage calculated by dividing the number of impressions that your campaign received for searches that exactly matched your keyword by the total estimated number of exact match impressions you were eligible to receive.
The impressions you’ve received divided by the estimated number of impressions you were eligible to receive on the Search Network for search terms that matched your keywords exactly (or were close variants of your keyword).
Read more here: https://support.google.com/adwords/answer/2497703?hl=en