[marsokod]

I was able to find the details (source in French: https://photo.capital.fr/shrinkflation-voici-la-liste-des-pr...)

In addition to the volume reduction, the price also went up from 1.45€ to 1.63€.

So the price per litre went from 0.97€/L to 1.36€/L. Much closer to the 40% figure.

[moritzwarhier]

Thanks for providing the only reply containing factual information.