Resources averege.
 

Why my resources average of income is so unstable? Sometimes my gold income is 13g p/min, sometimes it's 87, is the same for my others resources...
Is it any problem with my game or it's normal to be so unstable?

This is a problem with out math behind resources income calculations. We made it show average per minute as resources are getting dropped off. And this value always goes up and down - as your peasants can spend the first minute mining, and drop off everything together during the second minute. Hopefully we`ll come up with something better in the future.