Excel Chart - Dynamic Axis

[felix_k]

I create two simple line charts in excel - one with a shorter data range - where the chart shows an "dynamic" y-axis based on underlying data set. However, if I expand the data range of the very same chart, the y-axis starts with ZERO - although there is no value in the data range that gets even close to this value. Does anybody have an idea why this is working like this and how I can get an "dynamic" axis also with a larger data range? thanks for any useful hint - much appreciated!