Auto generation of over 200,000 numeric data item based on mathematical logic

Some back-engineering analysis are required to build a database of 200,000 numeric data item based on some logic. Ouput are available as mean but input need to be predicted using automated number generation . Mean is available per provinces (this numeric number will be distributed by provinces, such that each province has its mean) and some normal distribution logic to inform the development. The mean is monthly and maybe worked by to days following a logic too. The final output will be standardised in a model such that the mean can be changed monthly and the dataset will automatically generate new set of numbers following the preset logic Expertise and proven experience required There is an expected mean which now need to be worked back to