The job
Answer 17 benchmark questions from quarterly Treasury Bulletins, 2015 to 2025, and measure retrieval and generation separately so the bottleneck is visible.
What changed the numbers
Structure aware chunking keeps whole table rows together and prepends the section header. Every chunk carries year, month and source file, and the retriever filters on them before ranking.
The filter includes the following year, because the Treasury prints calendar year totals in the next March issue. Without that, one question's gold document was filtered out entirely.
Results
Doc hit rate at five went from 11.8% to 58.8%, and recall from 5.9% to 47.1%. Factual accuracy only moved from 0% to 5.9%, one question in 17.
The write-up says why: retrieval finds the right bulletin but never the exact cell, and most gold answers are statistics that are never printed in the source.