At that point was Google already using deep learning for search? I'd guess the number fluctuated a bit during the rollout of this kind of feature
Various ML "learn-to-rank" tooling was in use at Google for a while, but incorporating document embedding vectors w/ ANN search into the ranking function probably happened over the course of 2018-2021 [1], I think. Generative AI only started appearing in ordinary search results in 2024.
1: https://cloud.google.com/blog/topics/developers-practitioner...