Methods
createDataVis()
Called the first time the page is loaded to setup the visualisation
drawDataVis()
Animate the rendering of the stack bar chart, the legend and the percentage values within the legend
initialiseDataVis()
Setup the wrapper and the bounds for the visualisation
redrawDataVis()
Animate the bars transitioning to the updated data set and change the percentage values in the legend
setScales()
Setup the scales for the visualisation
updateDataVis()
When the data set is updated this will cause the visualisation to animate