VizFrame column chart doesn't cummulate values for y-axis

Hello everyone,

i'm trying to implement a column chart to my SAPUI5 App. I would like to accomplish that by using a VizFrame Chart of type column. Now my problem is that the chart doesn't cummulate the y-axis value for a specific dimension. For example:

Here i would assume that the second column would show a value of 2,5 but i don't know to achieve this.

The data is provided by an odata service. This is the implementation in the xml view:

If further informations are needed please let me know. I will provide them as fast as possible.

Thanks in advance

Marvin