Y axis doesn't reflect the correct value

I am using elasticsearch 2.3.2 and kibana 4.5.1

when i discover, the value for the field is correct, the fs_used_p is 0.42

however when i try to draw chart with Y axis is Average of fs_used_p, the Y axis value keeps at 0, what is wrong with this? (I dont have any point with value=0), does anyone know what is wrong with this?

the 'auto' interval may be causing your average to really be zero or very low, what happens if you select another interval that you're sure to make sense?
Also, you can do a 'sum' instead of an average just to see if you have any value different than zero