How to calculate HHIs for very large DATASETS

In this video I draw a dataset from OAG for the entire Western European airline market and demonstrate how the route-level Herfindahl-Hirschmann Indicies (HHIs) can be calculated. The video will be of interest to any air transport analyst of graduate students of airline economics or geography.
HHI is calculated by squaring the market share for every player in the market and then summating the results. For example, if you have three airlines operating on a route. Airline A has 45% of the market, Airline B has 35% and Airline C has 20% the HHI would be:
HHI = (45^2 + 35^2 + 20^2)
HHI = 3,650