Plot graph from time series in columns

Hi, I have a spreadsheeet datasource that has time series data in columns

Jan-17 Feb-17 March-17 Apr-17
5             6           4                 3
3             4           3                 2
4             3           5                 3

I would like to be able to plot this as a sum of each month.

I have tried to do this by creating a measure for each month and calculating, however this does not plot properly as there is no x axis

Any ideas ?

Regards

Owen