Why did adSense revenue drop so much in 2015 (Table attached)?

Question

contextual advertising

On one of the resources, the income on the site dipped heavily. At what attendance grows, views grow. You try you try, and the income for half a year is like in one place.

Answer 1

site in Russia / CIS? everything is trite - advertisers pay less, in dollars, in rubles, maybe even higher when

Answer 2

The fee has grown a lot = competition for the rental of advertising spaces, and adblock is also "virally" put constantly ...