The values add up to 100%. To make sure this can be displayed properly the axis is expanded to 1 unit of scale beyond that maximum unless you manually specify another maximum. That's why the axis ends at 150%.
Perhaps you can change the scale setting from Medium (or Wide) to Narrow.
You can use an expression for the maximum setting of the scale. If you change from alternative measures to an inline table with measure names from which the user selects the measure then you could use the expression for the maximum setting to calculate a maximum value based on the measure the user selected.