Hello there,
I have noticed in the video that 2 graphs are inconsistent, and one of the chart must have been mislabeled somewhere (probably SCH and WHM inverted on the second).
It is mathematically impossible that WHM are more numerous in first piechart and less numerous than SCH in second. :)
Unless a different method was employed, which kind of negates the point of having the charts in the first place.
http://i.imgur.com/HeAaJWt.png