Publications at NeurIPS/ICML is a reasonable proxy for contribution to the field. https://medium.com/@chuvpilo/ai-research-rankings-2019-insig...
In 2019, the top 5 institutions were:
1. Google (USA) — 167.3
2. Stanford University (USA) — 82.3
3. MIT (USA) — 69.8
4. Carnegie Mellon University (USA) — 67.7
5. UC Berkeley (USA) — 54.0