Group by ZERO?

[koraliap]

Hello,
i am using Dashboard to produce some statistics based on scores. I want a pie which shows the
distribution of the score . It is a child graph from another user.
My code is

var scoreRangesPie = dash.createPieChart({
			container: "#svg2",
			groupBy: "result.score.scaled",
			range: {start: 0, end: 1, increment: 0.1},
			pre: function(data, event){
				return data.where('actor.mbox = "' + event.in + '"');
			},
			aggregate: ADL.count(),
			});

when my graph shows up, it does not have a slice for score.scaled=0, although my datas include statements with score.scaled='0. The graph shows correct all other scores but totally ignores statements with score=0.
I would be grateful if you had any clue.
Yours,
K.