How this is measured

The base fee adjusts block by block with demand under the chain's fee mechanism: sustained demand pushes it up, idle blocks let it decay back toward the floor. It is burned, not paid to validators; the priority tip is the part that buys inclusion order.

History is computed from every block in ClickHouse: each bucket's percentiles (p25, median, p75, p95) summarize the distribution of per-block base fees inside it, so the band shows what the fee actually was across the period, not a single sampled value. The live figure reads eth_feeHistory straight off the chain's public RPC.