Set maximum size for cells Highcharts heat map

Question

I cant find the way of setting a maximum size for the cells of a heat map.

It always go for the 100% of the space, it doesnt mind if I only use this data:

data: [[0,0,10],[0,1,19],[0,2,8],[0,3,24],[0,4,67],[1,0,92],[1,1,58],[1,2,78],[1,3,117],[1,4,48]],

http://jsfiddle.net/dJeUm/