Zoom using scroll on safari

[arscan]

When using Safari, it appears you have to have your cursor directly over the content of the graph in order to use the zoom in / zoom out using scrolling, at least when using the trackpad. Having it anywhere else on the page, including 'edges' of the chart area (anywhere outside the bounding box of the actual rendered content) does not appear to get captured by the library that handles zooming.

Chrome & Firefox have the correct behavior.