input standardization/normalization

Ive some problems with standardization/normalization inputs of my network.
How to normalize inputs like time and price between -1 and +1?
e.g.: The training data for the "price" is 10, 11, 12, 11, ...
The problem is, that I dont know how the price will be in the future. So I cant use Min = 10 and Max = 12. And I want my network to keep working, even if there is a hyperinflation and the price is very high.
How to normalize inputs like time and price between -1 and +1?
e.g.: The training data for the "price" is 10, 11, 12, 11, ...
The problem is, that I dont know how the price will be in the future. So I cant use Min = 10 and Max = 12. And I want my network to keep working, even if there is a hyperinflation and the price is very high.