Steps to reproduce:

1. Create item and generate some values. 
   Values:
   
2. Create graph widget. Add host and item as item list
   
3. Go to Legend tab. Click on checkbox for "Display min/avg/max"
4. In Data set tab change Y-axis from left to right

Actual:

1. Different numbers are shown for Y-axis, when it is on the left / right side
2. Different values are shown for legend avg

Screencast:

Expected:

Assume Y-axis position should not affect any numbers{}