In order to alter the metric format, the 'Show Labels' option must first be selected. For more information on this; use the link below!
To access these options click on the plus button found left of the metric name in the visualisation widget. This will reveal the metric options available:
To view the labels as the actual metric value and not as a percentage of the total, click the 'Full values for labels' button.
This value can then be formatted but clicking the 'Formatted' button to display something like this:
