Interesting article, although with so few data points and such a specific time slice it is difficult to draw serious conclusions about the "improvement" of LLM models.

It's notably lacking newer models (4.5 Opus, 4.6 Sonnet) and models from Gemini.

LLMs appear to naturally progress in short leaps followed by longer plateaus, as breakthroughs are developed such as chain-of-thought, mixture-of-experts, sub-agents, etc.