Help for Year Range Calculator !!!

 

Anyone know how to create Average Yearly Range Calculator ?? Range is based on High/Low of the year. I would like to put this on weekly chart on top left of chart.

Make it something like this indicator..

Output can be like :

=================

Average 20 years range: 2000

Previous year range: 1500

Current year range: 1100

 

Anyone can help ???

Pls pls pls.........

Reason: