> How many models are only trained on legal[0] data?

None, since 'legal' for AI training is not yet defined, but Olma is trained on the Dolma 3 dataset, which is

1. Common crawl

2. Github

3. Wikipedia, Wikibooks

4. Reddit (pre-2023)

5. Semantic Scholar

6. Project Gutenberg

* https://arxiv.org/pdf/2402.00159