Until a value has been entered for a metric, the metric is displayed on the report with a yellow bar:
To enter a value simply click in the grey box and type in the value for the metric.
Once a value has been entered the yellow bar disappears and the value is displayed:
To update the value, again just click in the grey box and enter the new value.
Or, to update all previous values you can click on the metric name to view and update details for the metric.