Its a another clever mind trick.
Is like cutting sandwiches in half horizontally or in half diagonally.
According to the physchologists, ad people marketing people etc, the diagonals look bigger although they arent.
In test when given the choice the majority of people will pick the triangles off as opposed to the obloids becaus the triangles look bigger
1 in 10 , 10 in 100 or 100 in thousand all the same as percentage but 10% sounds better as you scale up the numbers, so depending on what you want to portray you also need to pick how to depict the number
0.3 % sounds like next to nothing, but imagine if they were to put the figure in real terms ie billions of pounds or even as a fraction, wouldnt seem as small as 0.3 %.
Its just another way of showing a statistic to paint the picture and get a calculated (no pun intended) response.