Generates a plot of Norrington Table rankings for Oxford colleges.
Requires matplotlib. Exports an image to plot.png.
You should be able to download an excel file with Norrington data from 2006 onwards from the Oxford website. You can then use simple excel formulae to get a ranking for each college based on their score, and calculate a mean rank for each college. Then format the excel file more or less as given in the example and export as csv. Make sure the last column is the mean rank.