How to make the minimum axis option dynamic ?

I want to have my graph dynamically take the minimum data value as the minimum y-axis value for the graph. For example: If I have data from 40 - 100 range then I want my y-axis to start from 40 without me having to goto axis option and changing the minimum axis option to fixed. Now if I refresh the data and if it ranges from 60 - 120 then the y-axis shoud start from 60. Please Help!

Thanks!!