Google has recently updated the way Clicks, Impressions, and CTR Values are calculated, with mobile app properties being most affected. John Mueller, webmaster trends analyst at Google, clarified further; the Search Analytics Report now includes data from Knowledge Panels, Rich Snippets, and Local Results.
You will notice the change when you log into your Search Console and select the Search Analytics report. You will see a vertical line indicating the update, and when hovering over the line, you will see the option to "Learn more." You can see a screenshot of the Search Analytics report below:
If you click the "Learn more" link, you will be taken to the "Data anomalies in Search Console" page which highlights the change on the 27th April:
We refined our standards for calculating clicks and impressions. As a result, you may see a change in the click, impression, and CTR values in the Search Analytics report. A significant part of this change will affect website properties with associated mobile app properties. Specifically, it involves accounting for clicks and impressions only to the associated application property rather than to the website.
The most interesting part of the update comes from further clarification from John Mueller, at Google. John Mueller commented on the announcement, also confirming that the Search Analytics report now includes data from the Knowledge Panel, Rich Snippets, and the Local Results as Search impressions, and clicks:
We recently made some changes in how Search Console reports & calculates clicks and impressions in Search Analytics.
As a result, you may see a change in the click, impression, and CTR values shown there. For most websites, this change will be minimal. A significant part of this change will affect website properties with associated mobile app properties. Specifically, it involves accounting for clicks and impressions only to the associated application property rather than to the website. Other changes include how we count links shown in the Knowledge Panel, in various Rich Snippets, and in the local results in Search (which are now all counted as URL impressions).
John Mueller further clarified that impressions and clicks will only be counted if a URL is located in them.
To get an idea of how frequently your content appears in the knowledge graph, Rich Snippets or Local pack, you can use a tool called SEMrush. Just enter your domain, and then select "Organic Research -> Positions" in the left-hand menu.
On the right side of the page, you will see a percentage of keywords that trigger such display. You can see an example below: