Me too, I believe this may be a country-specific market share, meaning the figures are for Bulgaria. However it doesn't make sense since color share here is definitely not the one from the article. Maybe these figures are from Germany?
The registration plate on the car in the photo gives a clue, D for Deutschland!
In the UK, the exactly 400 cars for sale on Autotrader are split 249 petrol, 151 diesel. However, thats the split for the cars people want to sell, not necessarily the split for those they want to keep ( T-Jet vs M-Jet anyone? )
Everything however is "translated" in the article - currency, types of expenses, etc. So I would assume market shares also represent Bulgarian market...