Admob Revenue Problem

Hello my users are upto 5000+ on playstore and i have daily 1000 active peoples as i check in my FBDB firebase daily check in then why my revenue is so down its upto 0.5$ per day instead of 13 Clicks each day
My other apps are performing better as expected but my this Fact App hell no words.
Please tell how can i modify my app for better revenue
I have only 1 Interistial Ad that appears after every 20 Facts and a Rewarded Video after every 100 Facts He Read

It depends on CPC and which country from CPC comes

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