There is no specific figure for income from a mining rig. Income depends on many factors. Basically, these are the cost of electricity, equipment performance and the market price of bitcoin. For example, whatsminer m31s 80t machine brings from 4 to 20 dollars https://minery.io/hardware-store/whatsminer-m31s-80t/ . And again, the yield depends on the current value of the crypto coin. To calculate the approximate income, you must take into account all the accompanying nuances.