The index claims to represent "de facto levels of academic freedom across the world" to provide "a comprehensive overview of academic freedom in 179 countries and territories." It is produced by Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), the V-Dem Institute, the Scholars at Risk Network, and the Global Public Policy Institute.
In a 2024 update to its 2023 report, Latvia lands a highly creditable 20th place globally, coming well ahead of traditional centers of academic excellence such as France, the United Kingdom and the United States.
Estonia manages to secure second place in the global rankings, with Lithuania somewhat lower, but still in the top 30% to 40%.
For full details of the results and methodology employed in compiling the AFI see: https://academic-freedom-index.net/
The video below offers some explanations, too.