Click-through rate (CTR) is the ratio of clicks to impressions on a mobile advertising campaign. CTRs are calculated by taking the number of clicks on a mobile advertising campaign, dividing it by the overall impressions and then expressing the resultant figure in percentage terms.

Hello, SEO guys,

How to analysis of term “Impressions” and “CTR” in webmaster tool. Suppose I have 1 keyword that has impression in 80, change is 1233% and CTR is 1%. After update its impression is 113, change is 495% and CTR is 0%.
Please explain me.